High purity lipopeptides

ABSTRACT

The invention discloses highly purified daptomycin and to pharmaceutical compositions comprising this compound. The invention discloses a method of purifying daptomycin comprising the sequential steps of anion exchange chromatography, hydrophobic interaction chromatography and anion exchange chromatography. The invention also discloses a method of purifying daptomycin by modified buffer enhanced anion exchange chromatography. The invention also discloses an improved method for producing daptomycin by fermentation of  Streptomyces roseosporus . The invention also discloses high pressure liquid chromatography methods for analysis of daptomycin purity. The invention also discloses lipopeptide micelles and methods of making the micelles. The invention also discloses methods of using lipopeptide micelles for purifying lipopeptide antibiotics, such as daptomycin. The invention also discloses using lipopeptide micelles therapeutically.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application No.11/739,180, filed Apr. 24, 2007, now U.S. Pat. No. 8,058,238, which is acontinuation of U.S. patent application Ser. No. 10/747,485, filed Dec.29, 2003, now abandoned, which is a continuation of U.S. patentapplication Ser. No. 09/735,191 filed Nov. 28, 2000, now U.S. Pat. No.6,696,412, which claims the benefit of U.S. Provisional Application No.60/177,170, filed Jan. 20, 2000, all of which are incorporated byreference herein in their entireties.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a highly purified form of lipopeptides,including daptomycin, a lipopeptide antibiotic with potent bactericidalactivity against gram-positive bacteria, including strains that areresistant to conventional antibiotics. The present invention alsorelates to a process for preparing the highly purified form of thelipopeptide. The present invention further relates to micelles oflipopeptides. The present invention also relates to pharmaceuticalcompositions of the lipopeptide micelles and methods of using thesecompositions. The present invention also relates to methods of makinglipopeptide micelles from non-associated monomers of the lipopeptides,and for converting lipopeptide micelles to non-associated monomers. Thepresent invention also relates to a process for preparing lipopeptidesusing micelles that is easily scaled for commercial production.

BACKGROUND OF THE INVENTION

The rapid increase in the incidence of gram-positiveinfections—including those caused by antibiotic resistant bacteria—hassparked renewed interest in the development of novel classes ofantibiotics. One such class is the lipopeptide antibiotics, whichincludes daptomycin. Daptomycin has potent bactericidal activity invitro against clinically relevant gram-positive bacteria that causeserious and life-threatening diseases. These bacteria include resistantpathogens, such as vancomycin-resistant enterococci (VRE),methicillin-resistant Staphylococcus aureus (MRSA), glycopeptideintermediary susceptible Staphylococcus aureus (GISA),coagulase-negative staphylococci (CNS), and penicillin-resistantStreptococcus pneumoniae (PRSP), for which there are very fewtherapeutic alternatives. See, e.g., Tally et al., 1999, Exp. Opin.Invest. Drugs 8:1223-1238, hereafter “Tally”. Daptomycin's inhibitoryeffect is a rapid, concentration-dependent bactericidal effect in vitroand in vivo, and a relatively prolonged concentration-dependentpost-antibiotic effect in vivo.

Daptomycin is described by Baltz in Biotechnology of Antibiotics, 2ndEd., ed. W. R. Strohl (New York: Marcel Dekker, Inc.), 1997, pp.415-435, hereafter “Baltz.” Daptomycin, also known as LY 146032, is acyclic lipopeptide antibiotic that can be derived from the fermentationof Streptomyces roseosporus. Daptomycin is a member of the factorA-21978C₀ type antibiotics of S. roseosporus and is comprised of adecanoyl side chain linked to the N-terminal tryptophan of a cyclic13-amino acid peptide (FIG. 1). Daptomycin has an excellent profile ofactivity because it is highly effective against most gram-positivebacteria; it is highly bactericidal and fast-acting; it has a lowresistance rate and is effective against antibiotic-resistant organisms.The compound is currently being developed in a variety of formulationsto treat serious infections caused by bacteria, including, but notlimited to, methicillin resistant Staphylococcus aureus (MRSA) andvancomycin resistant enterococci (VRE).

A number of United States patents describe A-21978C antibiotics andderivatives thereof including daptomycin (LY 146032) as well as methodsof producing and isolating the A-21978C antibiotics and derivativesthereof.

U.S. Pat. Nos. Re. 32,333, Re. 32,455 and 4,800,157 describe a method ofsynthesizing daptomycin by cultivating Streptomyces roseosporus NRL15998under submerged aerobic fermentation conditions. U.S. Pat. No. 4,885,243describes an improved method of synthesizing daptomycin by feeding afermentation culture a decanoic fatty acid or ester or salt thereof.

U.S. Pat. Nos. Re. 32,310, Re. 32,311, 4,537,717, 4,482,487 and4,524,135 describe methods of deacylating the A-21978C antibiotic andreacylating the peptide nucleus and antibiotic derivatives made by thisprocess. All of these patents describe a purified deacylated A-21978Cantibiotic nucleus or a derivative thereof which was isolated from thefermentation broth by filtration and then purified by Diaion HP-20chromatography and silica gel/C18 chromatography.

U.S. Pat. Nos. Re. 32,333 and Re. 32,455 disclose a purification methodin which a filtrate of whole fermentation broth was purified through anumber of precipitation and extraction steps to obtain a crude A-21978Ccomplex. The crude complex was further purified by ion exchangechromatography on IRA-68 and two rounds of silica gel chromatography.Individual A-21978C factors were separated by reverse-phase silica gelor silica gel/C18. U.S. Pat. Nos. Re. 32,333 and Re. 32,455 alsodisclose that A-21978C may be purified by batch chromatography usingDiaion HP-20 resin followed by silica-gel column chromatography.

U.S. Pat. No. 4,874,843 describes a daptomycin purification method inwhich the fermentation broth was filtered and passed through a columncontaining HP-20 resin. After elution, the semipurified daptomycin waspassed through a column containing HP-20ss, and then separated again onHP-20 resin. The '843 patent states that final resolution and separationof daptomycin from structurally similar compounds by this method isimpeded by the presence of impurities that are not identifiable byultraviolet analysis of the fermentation broth. The '843 patent furtherstates that attempts to remove these impurities by reverse phasechromatography over silica gel, normal phase chromatography over silicagel or ion exchange chromatography also failed to significantly improvethe purity of daptomycin. The '843 patent also discloses a “reversemethod” for purification comprising the steps of contacting an aqueoussolution of the fermentation product with a non-functional resin inaqueous phase, physically removing the water from the charged resin,rewetting the charged resin with a polar organic solvent, washing theresin with the organic solvent, eluting the fermentation product fromthe resin by increasing the polarity of the solvent and recovering thefermentation product. The '843 patent teaches that this method improvesthe final purity from about 80% to about 93% and increases the yieldfrom about 5% to about 35%; however, the '843 patent does not disclosethe type of impurities present in the daptomycin preparation.

U.S. Pat. No. 5,912,226 describes the identification and isolation oftwo impurities produced during the manufacture of daptomycin.Daptomycin, an α-aspartyl peptide, becomes transpeptidated to form astable intermediate in which the aspartyl group becomes ananhydro-succinimido group (FIG. 3). The '226 patent teaches that thepresence of this intermediate, designated anhydro-daptomycin, is morepronounced at pH 4-6. Rehydration of the anhydro-succinimido formproduces a second degradation product that contains an β-aspartyl groupand is designated the β-isomer form of daptomycin (FIG. 2).

The '226 patent discloses that the t-BOC derivative ofanhydro-daptomycin may be isolated by chromatography over reverse phasesilica gel/C-18 column, precipitated, and repurified by reverse phasesilica gel/C-18 chromatography. The '226 patent also teaches that theβ-isomer form of daptomycin may be purified by chromatography over aDiaion HP-20ss resin, desalted by chromatography over a Diaion HP-20resin, and further purified using a reverse-phase C-18 column followedby a HP-20 resin column in reverse mode.

Kirsch et. al. (Pharmaceutical Research, 6:387-393, 1989, hereafter“Kirsch”) stated that anhydro-daptomycin and the β-isomer were producedin the purification of daptomycin. Kirsch described methods to minimizethe levels of anhydro-daptomycin and the β-isomer through manipulationof pH conditions and temperature conditions. However, Kirsch was unableto stabilize daptomycin and prevent the conversion of daptomycin toanhydro-daptomycin and its subsequent isomerization to β-isomer. Kirschwas also unable to prevent the degradation of daptomycin into otherdegradation products unrelated to anhydro-daptomycin and β-isomer.

The '226 patent states that daptomycin may be prepared using theseprocedures so that the daptomycin contains no more than 2.5% by weightof a combined total of anhydro-daptomycin and β-isomer, but gives noindication of the levels of other impurities. In the method taught inU.S. Pat. No. 4,874,843 and in large-scale preparations of daptomycinfor clinical trials, the highest daptomycin purity levels observed hasbeen about 90%-93%. There is a need for a commercially feasible methodto produce more highly purified daptomycin and, if possible, to increaseits yield after purification. Furthermore, it would be desirable toobtain purified daptomycin that contains little or none ofanhydro-daptomycin and the β-isomer form of daptomycin. It would also bedesirable to reduce the levels of a number of other impurities indaptomycin. However, there has been no method available in the art thathas been shown to be able to further reduce the levels ofanhydro-daptomycin, β-isomer form and other impurities in the daptomycinproduct.

SUMMARY OF THE INVENTION

The instant invention addresses these problems by providing commerciallyfeasible methods to produce high levels of purified lipopeptides. In apreferred embodiment, the lipopeptide is daptomycin or adaptomycin-related lipopeptide. In one embodiment of the instantinvention, commercially feasible methods are disclosed that results indaptomycin at a purity level of 95-97%. In another embodiment of theinstant invention, a commercially feasible method is disclosed thatalmost completely eliminates the major impurities anhydro-daptomycin andβ-isomer as well as other impurities in preparations of daptomycin. Inanother embodiment of the invention, commercially feasible methods aredisclosed for purifying lipopeptides, including daptomycin or adaptomycin-related lipopeptide, comprising separating lipopeptidemicelles from low molecular weight contaminants and separatingnon-associated lipopeptides from high molecular weight contaminants. Theinvention also provides high performance liquid chromatography (HPLC)methods of analyzing the purity of daptomycin and detecting andcharacterizing other impurities in daptomycin, some of which werepreviously unknown.

The invention also provides purified daptomycin that possesses a purityof at least 98% or that is substantially or essentially free ofanhydro-daptomycin and β-isomer. The invention provides purifieddaptomycin that is free or essentially free of anhydro-daptomycin andcontains a much lower level of the β-isomer and of other contaminantsthan was previously possible to obtain in the prior art. The inventionalso provides lipopeptide micelles. In a preferred embodiment, themicelle comprises daptomycin or a daptomycin-related lipopeptide. Theinvention also provides pharmaceutical compositions comprising highlypurified daptomycin or a daptomycin-related lipopeptide micelles andmethods of using these compositions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the structure of daptomycin.

FIG. 2 shows the structure of impurity 8, CB-131010 (previouslyidentified as the β-isomer, LY213846).

FIG. 3 shows the structure of impurity 13, CB-130952 (previouslyidentified as anhydro-daptomycin, LY178480).

FIG. 4 shows the proposed structure of impurity 1, CB-131012 (previouslyidentified as LY212218).

FIG. 5 shows the proposed structure of impurity 2, CB-131011.

FIG. 6 shows the proposed structure of impurity 3, CB-131008 (previouslyidentified as LY213928).

FIG. 7 shows the proposed structure of impurity 4, CB-131006.

FIG. 8 shows the proposed structure of impurity 6, CB-130989 (previouslyidentified as LY213827).

FIG. 9 shows the proposed structure of impurity 7, CB-131005.

FIG. 10 shows the proposed structure of impurity 12, CB-131009.

FIG. 11 shows the proposed structure of impurity 14, CB-131078(previously identified as LY109208).

FIG. 12 shows an HPLC chromatogram for a bulk preparation of daptomycin,including impurities 1 to 14.

FIG. 13 shows an HPLC chromatogram for a preparation of daptomycin afterpurification on a Poros P150 resin.

FIGS. 14A-14C show micellar structures. FIG. 14A shows a sphericalmicelle, in which the hydrophobic tails of amphipathic molecules areoriented toward the center of the sphere while the hydrophilic heads ofthe amphipathic molecules are oriented towards the outside of thesphere, in contact with the aqueous environment. FIG. 14A shows anexample in which the hydrophilic heads are negatively charged. FIG. 14Bshows a lipid bilayer structure in which two layers of amphipathicmolecules assemble such that the hydrophobic tails of each layer areoriented towards each other while the hydrophilic heads on either sideof the bilayer are in contact with the aqueous environment. Lipidbilayers may be either spherical or planar. FIG. 14C shows a liposome,in which a lipid bilayer, such as that shown in FIG. 14B, forms aspherical structure enclosing an aqueous interior. The hydrophilic headsof the liposome face the aqueous interior and the external aqueousenvironment.

FIG. 15 shows the results of an experiment to determine the criticalmicellar concentration (cmc) of daptomycin at pH 4.0.

FIG. 16 shows the size distribution of daptomycin micelles by lightscatter. The daptomycin micelles have an average size of 5.4 nm (54 A).

DETAILED DESCRIPTION OF THE INVENTION

Objects of the Invention

One object of the present invention is to provide a method for purifyinglipopeptides that is easily scaled for commercial production comprisinga unique combination of anion exchange chromatography and hydrophobicinteraction chromatography. In a preferred embodiment, the method isused to manufacture purified daptomycin that is greater than 95% pureand exhibits reduced levels of impurities compared to daptomycinprepared by prior art methods. In another preferred embodiment, themethod is used to manufacture daptomycin using reduced levels ofsolvents compared to those used in prior art methods. In anotherpreferred embodiment, the method is used to manufacture purifieddaptomycin-related lipopeptides that are greater than 95% pure.

Another object of the present invention is to provide a method forincreasing the levels of a lipopeptide produced by a microorganism byfeeding the fermentation culture a reduced level of a fatty acid. Usinglower levels of decanoic acid than those proposed for daptomycinfermentation in U.S. Pat. No. 4,885,243 results in improved economics inaddition to producing a highly pure form of daptomycin or adaptomycin-related lipopeptide. In a preferred embodiment, the method isused to increase the concentration and amount of daptomycin produced byStreptomyces roseosporus while minimizing the production of relatedcontaminants. Lower levels of contaminants in the fermentation brothresults in a more efficient recovery and purification of daptomycin,which provides for a manufacturing process with a higher yield.

Another object of the present invention is to provide a method forpurifying daptomycin or daptomycin related lipopeptides comprising theuse of modified buffer enhanced anion exchange chromatography. In apreferred embodiment, the method is used to produce daptomycin that isat least 98% pure or that is substantially or essentially free ofanhydro-daptomycin or β-isomer. In another preferred embodiment, themethod is used to purify daptomycin-related lipopeptides to at least 98%purity.

Another object of the present invention is to provide a processchromatography method to purify a lipopeptide comprising a novelcombination of anion exchange chromatography, hydrophobic interactionchromatography and modified buffer enhanced anion exchangechromatography. In a preferred embodiment, the process chromatographymethod is used to purify daptomycin or a daptomycin-related lipopeptide.The modified buffer unexpectedly permits a separation ofanhydro-daptomycin from daptomycin not previously possible in priorchromatography methods.

Another object of the invention is to provide a method for purifyinglipopeptides that is easily scaled for commercial production usinglipopeptide micelles. In one embodiment, the method comprises convertinga lipopeptide solution from a monomeric, nonmicellar state to a micellarstate and back again during purification procedures. In a preferredembodiment, the method comprises subjecting the lipopeptides toconditions in which micelles are formed, separating the lipopeptidemicelles from low molecular weight contaminants by, e.g., a sizeseparation technique. In another preferred embodiment, the methodcomprises subjecting the lipopeptides to conditions in which thelipopeptides are in monomeric form and separating the monomericlipopeptide molecules from high molecular weight molecules or aggregatesby, e.g., a size separation technique. In a more preferred embodiment,the method comprises both steps: subjecting the lipopeptides toconditions in which micelles are formed and separating the lipopeptidemicelles from low molecular weight contaminants, and then subjecting thelipopeptide micelles to conditions in which the lipopeptides are inmonomeric form and separating the lipopeptide monomers from highmolecular weight molecules or aggregates. These two steps may beperformed in either order. In an even more preferred embodiment, thesize separation technique is ultrafiltration or size exclusionchromatography.

A further object of the present invention is to provide improved methodsfor measuring the purity of lipopeptides, including daptomycin, by highpressure liquid chromatography (HPLC).

Another object of the present invention is to provide purifiedlipopeptides, such as daptomycin or a daptomycin-related lipopeptide,and pharmaceutically acceptable salts or formulations thereof. In apreferred embodiment, the present invention provides daptomycin or adaptomycin-related lipopeptide purified by one of the methods describedin the specification. The present invention also provides pharmaceuticalcompositions of a purified lipopeptide or its salts and methods ofadministering these compositions. In a preferred embodiment, thepharmaceutical composition comprises purified daptomycin.

Another object of the present invention is to provide lipopeptidemicelles and pharmaceutically acceptable formulations thereof. In apreferred embodiment, the present invention provides daptomycin micellesor a daptomycin-related lipopeptide micelle and pharmaceuticallyacceptable formulations thereof. In another embodiment, the inventionalso provides methods of administering the lipopeptide micelles orpharmaceutical formulations thereof to patients in need thereof. In apreferred embodiment, the lipopeptide micelles are administeredintravenously, parenterally, intramuscularly or topically.

Definitions

Unless otherwise defined, all technical and scientific terms used hereinhave the meaning as commonly understood by one of ordinary skill in theart to which this invention belongs. The practice of the presentinvention employs, unless otherwise indicated, conventional techniquesof chemistry, biochemistry and microbiology and basic terminology usedtherein.

The term “isolated” refers to a compound or product that is refers to acompound which represents at least 10%, preferably at least 20% or 30%,more preferably at least 50%, 60% or 70%, and most preferably at least80% or 90% of the compound present in the mixture.

The term “lipopeptide” refers to a molecule that comprises a lipid-likemoiety covalently linked to a peptide moiety, as well as salts, esters,amides and ethers thereof. The term “lipopeptide” also encompassesprotected forms of lipopeptides in which one or more amino, carboxylateor hydroxyl groups are protected. See, e.g., “Protective Groups inOrganic Synthesis” by Theodora W. Greene, John Wiley and Sons, New York,1981 for examples of protecting groups. In a preferred embodiment, thelipopeptide is an antibiotic. In another preferred embodiment, thelipopeptide is LY 303366, echinocandins, pneumocandins, aculeacins,surfactin, plipastatin B1, amphomycin or the lipopeptide derivativedisclosed in U.S. Pat. No. 5,629,288. These lipopeptides are known inthe art. See, e.g., U.S. Pat. No. 5,202,309 and International PCTApplication WO 00/08197. In another preferred embodiment, thelipopeptide is a daptomycin-related molecule, including, inter alia,daptomycin, A54145, a daptomycin-related lipopeptide disclosed in U.S.Pat. Nos. 4,537,717, 4,482,487, Re. 32,311, Re. 32,310, 5,912,226,currently in reissue as U.S. Ser. No. 09/547,357, U.S. ProvisionalApplications Nos. 60/170,943, 60/170,946 or 60/170,945, filed Dec. 15,1999, U.S. Provisional Application No. 60/208,222, filed May 30, 2000,all of which are specifically incorporated herein by reference, or anA-21978 antibiotic in which the n-decanoyl fatty acid side chain ofdaptomycin is replaced by an n-octanoyl, n-nonanoyl, n-undecanoyl,n-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acid side chain.The daptomycin-related lipopeptides disclosed in 60/170,943, 60/170,946,60/170,945, and 60/208,222 relate to synthetic and semisyntheticlipopeptides in which the ornithine or kynurine residues or the fattyacid side chain of daptomycin are modified. In a more preferredembodiment, the lipopeptide is daptomycin. The term daptomycin-relatedlipopeptide refers to compounds described above, and salts thereof.

The term “daptomycin” refers to the n-decanoyl derivative of the factorA-21978C₀ type antibiotic, or a pharmaceutical acceptable salt thereof.“Daptomycin” is synonymous with LY146032. See FIG. 1.

The term “anhydro-daptomycin” refers to the daptomycin derivative inwhich the α-aspartyl group of daptomycin is transpeptidated to ananhydro-succinimido group. See FIG. 3.

The term “β-isomer” or “β-isomer of daptomycin” refers to the daptomycinderivative that contains a β-aspartyl group instead of an α-aspartylgroup. See FIG. 2.

Daptomycin or a daptomycin-related lipopeptide is “substantially pure”when at least 95% of a sample is daptomycin or daptomycin-relatedlipopeptide. Preferably, daptomycin or daptomycin-related lipopeptide is“substantially pure” when at least 97% of a sample is daptomycin ordaptomycin-related lipopeptide.

Daptomycin or daptomycin-related lipopeptide is “essentially pure” whenat least 98% of a sample is daptomycin or daptomycin-relatedlipopeptide. Preferably, daptomycin or daptomycin-related lipopeptide is“essentially pure” when at least 99% of a sample is daptomycin ordaptomycin-related lipopeptide.

Daptomycin or daptomycin-related lipopeptide is “substantially free” ofanother compound when the other compound is present in an amount that isno more than 1% of the amount of the daptomycin or daptomycin-relatedlipopeptide preparation.

Daptomycin or daptomycin-related lipopeptide is “essentially free” ofanother compound when the other compound is present in an amount that isno more than 0.5% of the amount of the daptomycin or daptomycin-relatedlipopeptide preparation.

Daptomycin or daptomycin-related lipopeptide is “free” of anothercompound when the other compound is present in an amount that is no morethan 0.1% of the amount of the daptomycin or daptomycin-relatedlipopeptide preparation. Alternatively, daptomycin or daptomycin-relatedlipopeptide is “free” of another compound when the compound cannot bedetected by HPLC under conditions of maximum sensitivity in which alimit of detection is approximately 0.05% or less of the amount of thedaptomycin or daptomycin-related lipopeptide preparation. Exemplary HPLCmethods are described herein (Tables 1 and 2).

“Purified” daptomycin or daptomycin-related lipopeptide refers tosubstantially pure daptomycin or daptomycin-related lipopeptide,essentially pure daptomycin or daptomycin-related lipopeptide, or a saltthereof, or to daptomycin, daptomycin-related lipopeptide, or a saltthereof which is substantially free, essentially free, or free ofanother compound.

“Partially purified” daptomycin or daptomycin-related lipopeptide refersto daptomycin, daptomycin-related lipopeptide, or a salt thereof that isless than 90% pure.

The purity of daptomycin, daptomycin-related lipopeptide or of anotherlipopeptide refers to the lipopeptide prior to its formulation in apharmaceutical composition. The purity may be measured by any meansincluding nuclear magnetic resonance (NMR), gas chromatography/massspectroscopy (GC/MS), liquid chromatography/mass spectroscopy (LC/MS) ormicrobiological assays. A preferred means for measuring the purity ofdaptomycin is by analytical high pressure liquid chromatography (HPLC).

The term “micelle” refers to aggregates of amphipathic molecules. In anaqueous media, the lipophilic domains of the molecules of the aggregateare oriented toward the interior of the micelle and the hydrophilicdomains are in contact with the medium. Micelle structures include, butare not limited to, spherical, laminar, cylindrical, ellipsoidal,vesicular (liposomal), lamellar and liquid crystal. See FIG. 14.

The term “mixed micelle” refers to a particular type of micelle in whichthe micelle contains more than a single type of amphipathic molecule. Inthe context of this invention, mixed micelles contain a lipopeptide andat least one other amphipathic molecule which may be anotherlipopeptide. Mixed micelles contain at least 10% of the lipopeptide byweight. In other embodiments, a mixed micelle contains at least 20%,30%, 40%, 50%, 60%, 70%, 80% or 90% of the lipopeptide.

The term “micellar solution” refers to a solution in which more than 50%of the lipopeptide molecules in the solution are present in micelles, asmeasured by weight. Preferably, at least 60%, 70%, 80%, 90% or 95% ofthe molecules are present in micelles. A micellar solution is retainedon a ultrafiltration membrane that has a 10,000 dalton nominal molecularweight (NMW) cutoff.

The term “critical micelle concentration” (cmc) refers to the particularconcentration of molecules, which is dependent upon temperature, saltconcentration and the nature and type of amphipathic molecule. Above thecmc, the unassociated monomers and micelles exist in equilibrium.

The term “monomer” refers to an amphipathic molecule that is not part ofan aggregate but that exists as a single molecule. In the context ofthis invention, the term monomer refers to a non-associated lipopeptide.

The term “monomeric solution” refers to a solution in which more than50% of the lipopeptide molecules are present as monomers as measured byweight. Preferably at least 60%, 70%, 80%, 90% or 95% are present asmonomers. A monomeric solution is not retained on a ultrafiltrationmembrane that has a 10,000 dalton NMW cutoff but rather passes throughthe membrane.

The term “low ionic strength buffer” refers to a solution that has asalt concentration below 50 mM; the term “medium ionic strength buffer”refers to a solution that has a salt concentration between 50-250 mM;the term “high ionic strength buffer” refers to a solution that has asalt concentration greater than 250 mM.

Methods for Manufacturing Purified Lipopeptides

One embodiment of the present invention is drawn to a processchromatography method that produces a purified lipopeptide in acommercially feasible manner. In a preferred embodiment, the lipopeptideis daptomycin or a daptomycin-related lipopeptide. The processchromatography method comprises sequentially using anion exchangechromatography, hydrophobic interaction chromatography (HIC) and anionexchange chromatography to purify a preparation containing alipopeptide, such as daptomycin or a daptomycin-related lipopeptide.

In a preferred embodiment of the instant invention, the purificationmethod further comprises altering the fermentation conditions in whichthe A21978C-containing crude product is produced by Streptomycesroseosporus in order to increase daptomycin production and decreaseimpurities and related contaminants produced by the S. roseosporusfermentation culture.

A preferred embodiment of the process chromatography method is describedbelow:

Streptomyces roseosporus is fermented with a feed of n-decanoic acid, asdisclosed in U.S. Pat. No. 4,885,243, with the modification that thedecanoic acid feed is kept at the lowest levels possible withoutdiminishing the overall yield of the fermentation. In a preferredembodiment, the residual decanoic acid is maintained at less than 50parts per million (ppm) during aerobic fermentation. In a more preferredembodiment, the residual decanoic acid is maintained between one and 20ppm during aerobic fermentation. In an even more preferred embodiment,the residual decanoic acid is maintained at approximately ten ppm duringaerobic fermentation. In a preferred embodiment, the concentration ofresidual decanoic acid is measured throughout fermentation and the feedlevel of decanoic acid is adjusted to continuously keep the residualdecanoic acid levels within the preferred parameters. The prior art doesnot describe the in situ specific and low residual constant decanoicacid concentrations required to achieve optimal expression of daptomycincontaining lower levels of impurities.

After fermentation, the extracellular solution is clarified by removingthe mycelia from the fermentation broth. Removing the mycelia from thefermentation is performed by any standard separation technique, such ascentrifugation or microfiltration. In a preferred embodiment, thefermentation broth is clarified by microfiltration, such as by using aPall Sep™ membrane system. In a more preferred embodiment, thefermentation broth is clarified using an industrial centrifuge, such asa Westfalia™ centrifuge, followed by a finishing depth filter. Otherdevices, such as filter presses, rotary drum filters or disposable depthfilters, may be used to remove mycelia from fermentation broth toproduce a clarified broth suitable for large-scale columnchromatography.

In another embodiment, daptomycin may be extracted from mycelialfermentation directly by using an organic solvent such as butanol priorto clarification on a solvent separating centrifuge or filter. Anyalcohol with four carbons or more may be used in the extractionaccording to this embodiment. A preferred solvent is n-butanol. Using anorganic solvent results in an initial additional purification ofdaptomycin compared to a purely aqueous separation of daptomycin. Forexample, daptomycin partitions into n-butanol when n-butanol is used ina concentration greater than 10% and when the process is conducted underconditions in which the n-butanol forms a separate phase, e.g., at a pHvalue of 4-5, which is near the isoelectric point of daptomycin (seeExample 4).

In another embodiment, daptomycin is produced in an immobilized reactorthat uses preactivated mycelia for the non-fermentation production ofdaptomycin using an energy source, preferably a sugar, elementalcomponents, such as amino acids and ammonia, and decanoic acid.Production of daptomycin in an immobilized enzyme reactor is thenprocessed by methods described herein.

After clarification of the fermentation broth, the levels of daptomycinare enriched, (i. e. concentrated) in the clarified solution by anionexchange chromatography. The clarified solution is first contacted withan anion exchange resin under conditions in which most or all ofdaptomycin binds to the anion exchange resin. After binding, the resinis washed with an appropriate ionic aqueous buffer to remove unboundmaterial and some of the daptomycin impurities. Finally, the purifieddaptomycin bound to the resin is eluted under conditions in whichdaptomycin will dissociate from the resin.

The binding, washing and elution steps may be performed according tothis invention using buffers and methods known in the art. For instance,elution may be performed by using a buffer containing an elevated saltconcentration compared to the wash buffer, a buffer that has a lower pHcompared to the wash buffer, or a buffer that has both a higher saltconcentration and a lower pH than the wash buffer. In a preferredembodiment, daptomycin is bound to the anion exchange resin that hasbeen equilibrated in a buffer containing no added salt or a low saltconcentration at a pH that is neutral to basic. The loaded resin iswashed with three column bed volumes of water and then three to six bedvolumes of an intermediate salt buffer containing 30 to 60 mM NaCl.Daptomycin is eluted from the column with one to three column volumes ofan elevated salt and/or lower pH buffer containing 300 to 500 mM NaCl.Higher concentrations of sodium chloride and alternative salts such aspotassium chloride will also elute daptomycin from the resin. In apreferred embodiment, a high flow rate anionic exchange resin is used.In a more preferred embodiment, FP-DA 13 resin (Mitsubishi) is used.

The anion exchange chromatography may be performed by columnchromatography or may be accomplished in batch mode. For commercialproduction, it may be preferred to use batch mode. The anion exchangeresin may be washed and eluted with stepwise salt gradients or with acontinuous salt gradient. A suitable stepwise or continuous saltgradient is any one that permits the separation of daptomycin fromcontaminants. In a preferred embodiment, a continuous salt gradient isone which ranges from 0 to 1000 mM NaCl. In a more preferred embodiment,a continuous salt gradient is one which ranges from 100 to 500 mM NaClor from 0 to 400 mM NaCl. Radial flow chromatography may also be used,as described in U.S. Pat. Nos. 5,756,680, 4,865,729, 4,840,730 or4,708,782.

After anion exchange chromatography, the daptomycin preparation isfurther purified by hydrophobic interaction chromatography (HIC). Oneembodiment of this step is described in U.S. Pat. No. 4,874,843, hereinincorporated by reference. The eluted aqueous daptomycin preparation iscontacted with a HIC resin under conditions in which most or all ofdaptomycin will bind to the resin. The water content of thedaptomycin-loaded resin is reduced by contacting the resin with anincreased concentration of a non-polar solvent. The resin is washed withan appropriate polar organic solvent under conditions in whichimpurities dissociate from the resin while daptomycin remains bound.Finally, the daptomycin preparation is eluted under conditions in whichdaptomycin dissociates from the resin. In general, daptomycin is elutedusing a solvent-containing buffer with a lower polarity (higher polarsolvent level) and/or higher pH than the wash buffer.

In a preferred embodiment, the non-functional resin for HIC is smallparticle HP-20ss (Mitsubishi). The bound daptomycin is specificallyremoved from the HP-20ss resin with an organic phase solvent, such asone containing isopropyl alcohol, acetonitrile, butanol or othersuitable solvent. In a more preferred embodiment, daptomycin is bound toHP-20ss resin that has been equilibrated in an acetate buffer containing10% acetonitrile or equivalent polar solvent, such as isopropyl alcohol.The daptomycin-loaded resin is washed with at least three column bedvolumes of equilibration buffer. The daptomycin-loaded resin is furtherfreed of additional impurities by washing with three to six bed volumesof an acetate wash buffer containing a non-eluting concentration of thepolar solvent. In a preferred embodiment, the daptomycin-loaded resin iswashed with 30% acetonitrile or 45% isopropyl alcohol. Thedaptomycin-loaded resin is eluted with one to three bed volumes ofacetate buffer containing 35% or more acetonitrile or greater than 50%isopropyl alcohol. In a preferred embodiment, daptomycin is eluted with35% acetonitrile at pH 4.0-5.0 or 55-60% isopropyl alcohol. In anotherembodiment, the daptomycin-loaded resin is eluted with one to three bedvolumes of buffer at an increased pH. In this embodiment, the pH of thebuffer is gradually increased to elute different compounds from thecolumn at different rates due to charge differences. At elevated pH,e.g., pH 6.0-7.0, the elution concentration of acetonitrile is reducedto 10-20%. Similarly, at elevated pH, e.g., pH 6.0-7.0 the elutionconcentration of isopropyl alcohol is reduced to 20-25%. Control of thetemperature under which chromatography is performed also influencessolvent concentration. Elution at lower temperatures, i.e., underrefrigerated conditions, requires increased levels of solvent at all pHconditions.

After HIC, the organic solvent in the daptomycin preparation is reducedby anion exchange chromatography. In a preferred embodiment, FP-DA 13 isused as discussed supra.

After the second anion exchange chromatography, the purified daptomycinis depyrogenated, filtered and concentrated under refrigeratedconditions. Filtering daptomycin may be performed by any method known inthe art. In one embodiment, filtering and depyrogenating may beperformed by:

i) providing a daptomycin solution under conditions in which thedaptomycin is in a monomeric and nonmicellar state;

ii) filtering the daptomycin solution under conditions in which thedaptomycin will pass through the filter but pyrogens will not passthrough the filter, e.g., having the daptomycin solution at pH 6.0-8.0and filtering the solution with an ultrafilter that is rated between3,000 NMW and 30,000 NMW;

iii) altering the daptomycin solution that has passed through the filtersuch that the daptomycin aggregates, e.g., by changing the pH of thedaptomycin solution to 2.5-4.5 such that daptomycin forms micelles;

iv) filtering the daptomycin solution under conditions in which thedaptomycin will be retained on the filter, e.g., concentrating thedaptomycin on an ultrafilter of 30,000 NMW or less, such as a reverseosmosis membrane; and

v) collecting the depyrogenated daptomycin.

In a preferred embodiment, daptomycin of step (ii) is filtered underpressure on a 10,000 dalton molecular weight cutoff (MWCO) ultra-filterat a pH of approximately 7-8. In a more preferred embodiment, daptomycinis at an initial concentration of less than 40 mg/ml, more preferably,at a concentration of approximately 31.25 mg/mL. Under these conditions,daptomycin passes through the filter but pyrogens such aslipopolysaccharides (LPS) do not. After the initial ultra-filtration,the pH of the filtrate is lowered to pH 2.5 to 4.5 and the filtrate isconcentrated on a 10,000 MWCO ultra-filter to approximately 120 mg/mL.Under these conditions, daptomycin is retained on the filter. In apreferred embodiment, the pH of the filtrate is pH 3.5. Subsequent toconcentration, the concentration of daptomycin is adjusted to 105 mg/mL,checked for endotoxin levels, and used to fill vials under asepticconditions.

In another embodiment, reverse osmosis nanofiltration is performed at pH1.5-3.0. The low pH and refrigerated conditions are used to retarddegradation of purified daptomycin. Daptomycin may be further filteredthrough a 0.2 μm filter to reduce bioburden and then lyophilized eitherin bulk or in vials.

As an alternative to the above ultra-filtration and concentration step,the eluted fractions containing daptomycin are mixed with butanol(either n-, iso- or t-butanol) at a pH of approximately 4.5, in a ratioof greater than one part butanol to nine parts daptomycin solution. In apreferred embodiment, one part butanol is mixed with four partsdaptomycin solution to yield a 20% butanol solution. Thebutanol-daptomycin solution is allowed to separate into organic andaqueous phases. Daptomycin partitions into the organic phase, which iscollected. The dehydration of daptomycin in the organic solvent maystabilize daptomycin and prevent the degradation of the purifieddaptomycin to anhydro-daptomycin and subsequent formation of β-isomer.Finally, daptomycin can be returned to the aqueous phase by addingbuffer at pH 6.5-7.5 to the organic phase. After concentration orcollection of daptomycin, daptomycin is lyophilized.

In another embodiment of the instant invention, the processchromatography method is used to purify lipopeptides other thandaptomycin, such as A54145, LY303366, echinocandins, pneumocandins,aculeacin, surfactin, plipastatin B1, amphomycin or the lipopeptidederivative disclosed in U.S. Pat. No. 5,629,288. In another embodiment,the process chromatography method is used to purify daptomycin-relatedlipopeptides, including A54145, or a lipopeptide disclosed in U.S. Pat.Nos. 4,537,717, 4,482,487, Re. 32,311, Re. 32,310, 5,912,226, currentlyin reissue as U.S. Ser. No. 09/547,357, U.S. Provisional ApplicationsNos. 60/170,943, 60/170,946 or 60/170,945, filed Dec. 15, 1999, U.S.Provisional Application No. 60/208,222, filed May 30, 2000, or anA-21978 antibiotic in which the n-decanoyl fatty acid side chain ofdaptomycin is replaced by an n-octanoyl, n-nonanoyl, n-undecanoyl,-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acid side chain.

In another embodiment of the instant invention, a “Salt Cloud Method”[Genetic Engineering News, Vol. 19, No. 20, pages 1, 34 and 43, (Nov.15, 1999)] is used in the purification of daptomycin or otherlipopeptides. The Salt Cloud Method is a membrane-based system thatcombines selective separations with high-volume throughput. The SaltCloud Method can be used in conjunction with those process stepsdisclosed herein or separately to purify daptomycin or otherlipopeptides.

Another embodiment of the instant invention is drawn to a chromatographymethod that produces a highly purified lipopeptide not achievable byprior art chromatography methods. The chromatography method comprisesthe use of modified buffer enhanced anion exchange chromatography topurify a preparation containing a lipopeptide. In a preferredembodiment, the method is used to produce highly purified daptomycin ora daptomycin-related lipopeptide. This method, when used with partiallypurified daptomycin, produces daptomycin that is at least 98% pure. Themethod also produces daptomycin that is free or essentially free ofanhydro-daptomycin. The method comprises the following steps:

Partially purified daptomycin is prepared by any method known in the artor as described herein. The daptomycin preparation is then furtherpurified by modified buffer enhanced anion exchange chromatography.Daptomycin is bound to anion exchange resin in the presence of anappropriate ionic modified buffer under conditions in which daptomycinbinds to the resin ion in a monomeric and non-micellar state. Themodified buffer comprises a buffering agent, such as, withoutlimitation, acetate, phosphate, citrate and Tris-HCl, or any otherbuffering agent that buffers well at neutral pH. The modified bufferfurther comprises one or more chaotropic agents, including, withoutlimitation, guanidine, ammonia, urea, a strong reducing agent, benzoate,ascorbate or another ionic enhancer capable of modifying the buffer sothat daptomycin is easily separated from impurities. Thedaptomycin-loaded resin is washed with an appropriate ionic modifiedbuffer to elute impurities, including anhydro-daptomycin. Daptomycin isthen eluted under conditions that permit the separation of daptomycinfrom impurities that remain bound to the resin, including the β-isomer.

In a preferred embodiment, the modified buffer is at a neutral pH (a pHof 6 to 8) and contains 2 to 6 M urea. In a further preferredembodiment, the anion exchange resin is Porous Resin P150 or Porous D50(PE Biosystems). In a more preferred embodiment, the anion exchangeresin is Porous P150. In a preferred embodiment, daptomycin is bound tothe resin in a low ionic strength buffer, washed with a low to mediumionic strength buffer and eluted with a high ionic strength buffer. Inone preferred embodiment, daptomycin is bound to the Porous P150 resinin a Tris buffer pH 7.0 containing 6 M urea. The daptomycin-loadedPorous P150 resin is washed with three bed volumes of Tris buffer orother suitable buffer containing a salt level that removes contaminantsand anhydro-daptomycin without eluting daptomycin. Daptomycin is elutedfrom the Porous P150 resin with Tris buffer or other suitable bufferunder elevated salt conditions that will leave additional impurities,including a significant portion of β-isomer, bound to the column Inanother preferred embodiment, Poros P150 is used and daptomycin is boundto the resin in an acetate buffer pH 6.0 containing 2 M urea. Thedaptomycin-loaded Poros P150 resin is washed and eluted similar to themethod above except that an acetate buffer pH 6.0 containing 2 M urea isused. Product fractionation may be measured by HPLC or by UV monitoring.

The modified buffer enhanced anion exchange chromatography may beperformed by column chromatography or may be accomplished in batch mode.Radial flow chromatography may also be used, as described in U.S. Pat.Nos. 5,756,680, 4,865,729, 4,840,730 or 4,708,782. The modified bufferenhanced anion exchange resin may be washed and eluted with stepwisesalt gradients or with a continuous salt gradient. A suitable stepwiseor continuous salt gradient is any one that permits the separation ofdaptomycin from impurities including, but not limited to,anhydro-daptomycin and β-isomer. In a preferred embodiment, a continuoussalt gradient is 0 to 1000 mM NaCl. In a more preferred embodiment, thesalt gradient is 100 to 500 mM NaCl or 0 to 400 mM NaCl.

In another embodiment of the instant invention, modified buffer enhancedanion exchange chromatography is used to purify lipopeptide compoundsother than daptomycin. These lipopeptide compounds include, withoutlimitation, A54145, LY303366, echinocandins, pneumocandins, aculeacin,surfactin and plipastatin B1 (Tsuge et al., 1996, Arch. Microbiol.165:243-51) and lipopeptide derivatives as shown in U.S. Pat. No.5,629,288. In another embodiment, modified buffer enhanced anionexchange chromatography is used to purify a daptomycin-relatedlipopeptide such as A54145, or a lipopeptide disclosed in U.S. Pat. Nos.4,537,717, 4,482,487, Re. 32,311, Re. 32,310, 5,912,226, currently inreissue as U.S. Ser. No. 09/547,357, U.S. Provisional Applications Nos.60/170,943, 60/170,946 or 60/170,945, filed Dec. 15, 1999, U.S.Provisional Application No. 60/208,222, filed May 30, 2000, or anA-21978 antibiotic in which the n-decanoyl fatty acid side chain ofdaptomycin is replaced by an n-octanoyl, n-nonanoyl, n-undecanoyl,-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acid side chain.

In another embodiment of the instant invention, a novel combination ofprocess chromatography steps is used to purify daptomycin or adaptomycin-related lipopeptide. The method comprises anion exchangechromatography, small particle reverse phase chromatography and modifiedbuffer enhanced anion exchange chromatography. The purification methodmay further comprise altering the fermentation conditions in which theA21978C-containing crude product is produced by Streptomycesroseosporus. These methods produce daptomycin or a daptomycin-relatedlipopeptide that is at least 98% pure. In a preferred embodiment, themethods produce daptomycin or a daptomycin-related lipopeptide that ismore than 99% pure.

A preferred embodiment of the process chromatography method is describedbelow:

Streptomyces roseosporus is fermented with a feed of n-decanoic acid, asdisclosed in U.S. Pat. No. 4,885,243, with the modification that thedecanoic acid feed is kept at the lowest levels possible withoutdiminishing the overall yield of the fermentation as described supra. Inan alternative embodiment, a different feedstock may be used so long asit ultimately provides an n-decanoyl group for addition to thedaptomycin nucleus. Examples of these feedstocks are, withoutlimitation, decanoic amide, decanoic esters including butyl esters,crude sources of coconut or palm oil, animal source decanoic acid,various salts of decanoic acid, and petrochemical sources of decanoicacid. After fermentation, the extracellular solution is clarified asdescribed supra. In an alternative embodiment, daptomycin may beextracted from mycelia using an organic solvent such as n-butanol priorto clarification on a solvent separating centrifuge or filter asdescribed supra. After clarification of the fermentation broth, thelevel of daptomycin is enriched in the clarified solution first by anionexchange chromatography and then by HIC as described supra.

After completion of HIC, the organic solvent in the daptomycinpreparation is reduced by any method known in the art. In a preferredembodiment, the organic solvent is reduced by anion exchangechromatography, as described supra. Daptomycin should be eluted from thecolumn in a buffer compatible with the buffer required for the modifiedbuffer enhanced chromatography. Alternatively, the elution buffer may beexchanged for the modified buffer by reverse osmosis or filtration on a10,000 MWCO filter. In another preferred embodiment, the organic solventis reduced by evaporation or dilution in buffer. In a third preferredembodiment, the reverse phase chromatography solvent and residual saltis removed using reverse osmosis at pH 1.5-4.0 or ultrafiltration at pH2.5-4.5. The resultant product may be frozen for bulk storage or driedby lyophilization and then rehydrated in water or in the buffer used forthe modified buffer enhanced anion exchange chromatography.

Daptomycin is further purified by modified buffer enhanced anionexchange chromatography as described supra.

After modified buffer enhanced anion exchange chromatography, thepurified daptomycin is filtered and concentrated under refrigeratedconditions. Filtering daptomycin may be performed by any method known inthe art. In a preferred embodiment, daptomycin is depyrogenated andconcentrated as described supra. Alternatively, daptomycin may beconcentrated by reverse osmosis under refrigerated conditions at a pH of1.5 to 4. The low pH and refrigerated conditions are used to retard thedegradation of purified daptomycin.

As an alternative or in addition to the above filtration andconcentration step, the eluted fractions containing daptomycin from themodified buffer enhanced anion exchange chromatography may be mixed withbutanol (either n-, iso- or t-butanol) at a pH of approximately 4.5, ina ratio of greater than one part butanol to nine parts daptomycinsolution. In a preferred embodiment, one part butanol is mixed with fourparts daptomycin solution to yield a 20% butanol solution. Thebutanol-daptomycin solution is allowed to separate into organic andaqueous phases. Daptomycin partitions into the organic phase, which iscollected. The dehydration of daptomycin in the organic solvent maystabilize daptomycin and prevent the degradation of the purifieddaptomycin to anhydro-daptomycin and subsequent formation of β-isomer.

After concentration or collection of daptomycin, daptomycin islyophilized.

In another embodiment of the instant invention, the processchromatography is used to purify lipopeptides other than daptomycin,such as those described supra.

Formation of Lipopeptide Micelles and Methods of Use Thereof

Another embodiment of the invention provides lipopeptide micelles,methods for forming lipopeptide micelles and methods of using thelipopeptide micelles for lipopeptide purification and pharmaceuticalcompositions. In a preferred embodiment, the lipopeptide is adaptomycin-related molecule, including, inter alia, daptomycin, A54145,a daptomycin-related lipopeptide disclosed in U.S. Pat. Nos. 4,537,717,4,482,487, Re. 32,311, Re. 32,310, 5,912,226, currently in reissue asU.S. Ser. No. 09/547,357, U.S. Provisional Applications Nos. 60/170,943,60/170,946 or 60/170,945, filed Dec. 15, 1999, U.S. ProvisionalApplication No. 60/208,222, filed May 30, 2000, or an A-21978 antibioticin which the n-decanoyl side chain of daptomycin is replaced by ann-octanoyl, n-nonanoyl, n-undecanoyl, n-dodecanoyl, -tridecanoyl orn-tetradecanoyl side chain. In a more preferred embodiment, thelipopeptide is daptomycin.

Micelles are aggregates of amphipathic molecules. In aqueous media, thelipophilic parts of the molecules are oriented toward the interior ofthe micelle and the hydrophilic parts of the molecules are in contactwith the aqueous media. Micelles form spontaneously in a solutioncontaining amphipathic molecules if the concentration of the moleculesis high enough.

Micelle formation causes changes in several bulk physical properties ofa solution including changes in osmotic pressure, turbidity, electricalconductance, surface tension, co-ion and counterion activities (in thecase of ionic amphipathic molecules), refractive index, UV and NMRspectra, partial molar volume, viscosity, diffusion coefficient and dyesolubilization. The cmc can be determined by measuring one or more ofthese micelle-dependent physical properties as a function ofconcentration of the amphipathic molecule. The size and shape ofmicelles can be determined by dynamic laser light scattering,ultracentrifugation, viscosity and/or low-angle X-ray scatteringexperiments. Micelles can also exist in liquid crystal phases.

Lipopeptides may be aggregated into micelles by providing aconcentration of lipopeptide that is greater than the cmc of thelipopeptide. The cmc is dependent upon the nature of the lipopeptide andthe temperature, salt concentration and pH of the aqueous solutioncomprising the lipopeptide. With respect to the nature of thelipopeptide, the cmc of a lipopeptide is reduced by the addition of CH₂groups to the lipophilic carbon chains. Thus, given the cmc fordaptomycin at a particular salt concentration, temperature and pH, thenan A-21978 type antibiotic in which the n-decanoyl fatty acid side chainis replaced by n-octanoyl, or -nonanoyl fatty acid side chain will havea higher cmc, while an A-21978 antibiotic in which the n-decanoyl fattyacid side chain of daptomycin is replaced by an n-undecanoyl,n-dodecanoyl, -tridecanoyl or n-tetradecanoyl fatty acid side chain willhave a lower cmc relative to daptomycin.

In one embodiment of the invention, the cmc of a lipopeptide may bemanipulated by adding or subtracting a CH₂ group to the lipopeptide. Ina preferred embodiment, the lipopeptide is A-21978, in which then-decanoyl fatty acid side chain of daptomycin is replaced by ann-octanoyl, n-nonanoyl, n-undecanoyl, -dodecanoyl, n-tridecanoyl orn-tetradecanoyl fatty acid side chain. In another embodiment, one cancalculate the approximate cmc of a lipopeptide following the teachingsof the specification. Given the cmc for a lipopeptide such asdaptomycin, one may calculate the approximate cmc of a relatedlipopeptide in which the n-decanoyl fatty acid side chain is replaced byan n-octanoyl, n-nonanoyl, n-undecanoyl, n-dodecanoyl, n-tridecanoyl orn-tetradecanoyl fatty acid side chain. The above may be carried out bymethods known by one skilled in the art.

In another preferred embodiment, given the cmc for one lipopeptide, onecan calculate the approximate cmc for a lipopeptide that contains arelated peptide moiety. In a preferred embodiment, given the cmc fordaptomycin and the teachings of the prior art, one may readily determinethe cmc for a related lipopeptide such as A54145, a daptomycin-relatedlipopeptide disclosed in U.S. Pat. Nos. 4,537,717, 4,482,487, Re.32,311, Re. 32,310, 5,912,226, currently in reissue as U.S. Ser. No.09/547,357, U.S. Provisional Applications Nos. 60/170,943, 60/170,946 or60/170,945, filed Dec. 15, 1999, U.S. Provisional Application No.60/208,222, filed May 30, 2000.

In another embodiment of the invention, the cmc of a lipopeptide ismanipulated by changing the temperature of the solution comprising thelipopeptide. The cmc for a lipopeptide usually increases with increasingtemperature of the solution. Thus, micelle formation is promoted bydecreasing the temperature and is hindered by increasing thetemperature. For instance, a solution comprising a lipopeptide may formmicelles at 4° C. because at that temperature the cmc is lowered and thelipopeptide concentration is above the cmc; however, the samelipopeptide solution may be monomeric at 20° C. because the cmc hasincreased with the temperature and the lipopeptide concentration is nowbelow the cmc. Thus, in a preferred embodiment, the concentration of alipopeptide is higher than the cmc at one temperature and is lower thanthe cmc at another, higher temperature. In a more preferred embodiment,the lipopeptide is daptomycin or a daptomycin-related molecule, such asthose described supra. In an even more preferred embodiment, thelipopeptide is daptomycin.

In another preferred embodiment, the ability to manipulate the formationof micelles of a lipopeptide by using different temperatures to affectthe cmc is used in the purification of the lipopeptide. In a morepreferred embodiment, the lipopeptide is daptomycin or a relatedmolecule, such as those described supra. In an even more preferredembodiment, the lipopeptide is daptomycin. In another preferredembodiment, the ability to manipulate lipopeptide micelle formation byaltering the temperature is used to make pharmaceutical compositionsthat are micellar under certain temperature conditions and monomericunder other temperature conditions. In a preferred embodiment, thepharmaceutical compositions comprise daptomycin or a daptomycin-relatedlipopeptide, as described supra. In another preferred embodiment, thepharmaceutical compositions comprise daptomycin.

In a further embodiment of the invention, the addition of an electrolyteis used to decrease the cmc of an ionic lipopeptide. In a preferredembodiment, a salt, such as NaCl, is added to a solution comprisinglipopeptide to reduce the repulsion between charged groups in alipopeptide micelle. In a preferred embodiment, the lipopeptide isdaptomycin or a daptomycin-related molecule, such as that describedsupra. For instance, the peptide moiety of daptomycin contains threeaspartic acid residues and an L-threo-3-methylglutamic acid residues(3-MG), all of which would be charged at neutral pH. Thus, addition ofan electrolyte, such as NaCl or an equivalent salt, will decrease thecmc of daptomycin. In a preferred embodiment, the salt concentration isat least 100 mM. In a more preferred embodiment, the salt concentrationis 150 mM to 300 mM salt. In an even more preferred embodiment, the saltis NaCl.

A decrease in the cmc is also observed with addition of an electrolytefor other lipopeptides, such as molecules related to daptomycin thatcontain aspartic acid residues, 3-MG residues or other charged residues.Therefore, in a preferred embodiment, a salt is added to a solution todecrease the cmc of a daptomycin-related lipopeptide, such as A54145, adaptomycin-related lipopeptide disclosed in U.S. Pat. Nos. 4,537,717,4,482,487, Re. 32,311, Re. 32,310, 5,912,226, currently in reissue asU.S. Ser. No. 09/547,357, U.S. Provisional Applications Nos. 60/170,943,60/170,946 or 60/170,945, filed Dec. 15, 1999, U.S. ProvisionalApplication No. 60/208,222, filed May 30, 2000, or an A-21978 antibioticin which the n-decanoyl fatty acid side chain of daptomycin is replacedby an n-octanoyl, n-nonanoyl, n-undecanoyl, -dodecanoyl, n-tridecanoylor n-tetradecanoyl fatty acid side chain. In another embodiment, thesalt concentration is decreased in order to increase the cmc of an ioniclipopeptide. In a preferred embodiment, the ionic lipopeptide isdaptomycin or a daptomycin-related lipopeptide, as described supra.

In another preferred embodiment, the ability to manipulate the formationof micelles of a lipopeptide by altering electrolyte concentration toaffect the cmc is used in the purification of the lipopeptide. In a morepreferred embodiment, the lipopeptide is daptomycin or adaptomycin-related molecule, such as those described supra. In an evenmore preferred embodiment, the lipopeptide is daptomycin. In anotherpreferred embodiment, the ability to manipulate lipopeptide micelleformation by electrolyte concentration is used to make pharmaceuticalcompositions that are micellar at certain electrolyte concentrations andmonomeric under other electrolyte concentrations. In a preferredembodiment, the pharmaceutical compositions comprise daptomycin or adaptomycin-related lipopeptide, as described supra. In another preferredembodiment, the pharmaceutical compositions comprise daptomycin.

In another embodiment of the invention, the pH of a solution comprisinga lipopeptide is manipulated to influence the cmc of the lipopeptide. Ina preferred embodiment, the lipopeptide is daptomycin or adaptomycin-related molecule, such as those described supra. In an evenmore preferred embodiment, the lipopeptide is daptomycin. In oneembodiment, the pH is manipulated so that the concentration of alipopeptide is higher than the cmc at one pH and is lower than the cmcat another pH. For instance, for daptomycin, the cmc at pH 4.0 in waterat a temperature of 20-25° C. was much lower than at pH 6.0 or 7.5. AtpH 4.0, the cmc is approximately 400 μg/mL under these conditions. SeeFIG. 15. Further, daptomycin is monomeric even at 150 mg/mL daptomycinat pH 6.5 (wherein the salt concentration is 150 mM to 300 mM NaCl andthe temperature is 4° C.). Thus, for daptomycin, the cmc at pH 4.0 islower than in solutions of either higher pH or lower pH. The change incmc at different pH levels may also be used for other chargedlipopeptides, including lipopeptides that are related to daptomycin, asdescribed supra.

In another preferred embodiment, the ability to manipulate the formationof micelles of a lipopeptide by altering the pH to affect the cmc isused in the purification of the lipopeptide. In a more preferredembodiment, the lipopeptide is daptomycin or a daptomycin-relatedmolecule, such as those described supra. In an even more preferredembodiment, the lipopeptide is daptomycin. In another preferredembodiment, the ability to manipulate lipopeptide micelle formation bypH is used to make pharmaceutical compositions that are micellar at aparticular pH and monomeric under another pH. In a preferred embodiment,the pharmaceutical compositions comprise daptomycin or adaptomycin-related lipopeptide, as described supra. In another preferredembodiment, the pharmaceutical compositions comprise daptomycin.

In another aspect of the invention, the lipopeptide may be part of amixed micelle. A mixed micelle is one in which the lipopeptide forms amicelle with one or more other types of amphipathic molecules. Examplesof such amphipathic molecules include, without limitation, medium andlong chain fatty acids, phosphoglycerides (phospholipids),sphingomyelin, glycolipids and cholesterol. In one embodiment, mediumchain-length alcohols can be incorporated into the micelle, where theyreduce electrostatic repulsion and steric hindrance, thus lowering thecmc of the lipopeptide. In another embodiment, the addition of one ormore types of amphipathic molecules can be used to alter the structureof the micelle from a spherical micelle (See FIG. 14, part a) to a lipidbilayer structure (See FIG. 14, part b) or to a liposome structure (SeeFIG. 14 part c). In general, mixed micelles comprising phospholipidsand/or glycolipids will cause a spherical micelle to convert to a lipidbilayer structure, which serve as permeability barriers to ions and mostpolar molecules.

In another embodiment, the mixed micelle can be formed from two or moredifferent lipopeptides. For instance, the mixed micelle can be formedfrom daptomycin and another lipopeptide, such as A54145 or adaptomycin-related lipopeptide, as discussed supra. In anotherembodiment, the mixed micelle may comprise a lipopeptide along with oneor more therapeutically useful amphipathic molecules, such as anantibiotic, an anti-inflammatory or an anti-fungal agent, which areknown to those having ordinary skill in the art. In a preferredembodiment, the lipopeptide is daptomycin or a daptomycin-relatedlipopeptide such as A54145, the daptomycin-related lipopeptidesdisclosed supra, or an A-21978 antibiotic in which the n-decanoyl fattyacid side chain of daptomycin is replaced by an n-octanoyl, n-nonanoyl,n-undecanoyl, n-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acidside chain. In a more preferred embodiment, the lipopeptide isdaptomycin.

In another embodiment of the invention, the micelle, whether mixed orcomprising a single type of lipopeptide molecule, comprises alipopeptide that is therapeutically useful. In a preferred embodiment,the lipopeptide is an antibiotic. In an even more preferred embodiment,the lipopeptide is daptomycin. Daptomycin forms micelles ofapproximately 5.4 nm (54 A) at a concentration of 1 mg/mL at pH ofapproximately 4.0 in water. See FIG. 16.

In another preferred embodiment, the micelles comprise one or moredifferent types of therapeutic substances. In one embodiment, atherapeutic substance can be mixed with the lipopeptide in solution suchthat a micelle is formed from the lipopeptide and the therapeuticsubstance is trapped in the hydrophobic interior. In another embodiment,a therapeutic substance is mixed with a lipopeptide and one or moreother amphipathic molecules such that a mixed micelle is formed from thelipopeptide and other amphipathic molecules and the therapeuticsubstance is found in the hydrophobic interior. In a preferredembodiment, the therapeutic substance is an antibiotic, ananti-inflammatory or an anti-fungal agent. In a more preferredembodiment, the therapeutic substance is an antibiotic or antifungalagent disclosed infra. In another preferred embodiment, the therapeuticsubstance is soluble in a hydrophobic environment but is not soluble inan aqueous solution.

In another embodiment of the invention, the lipopeptides may be formedinto liposomes, which are vesicular micelles in which a spherical lipidbilayer surrounds an aqueous interior. See FIG. 14, part c. Liposomesare advantageous for therapeutic uses because they easily fuse with aplasma membrane and can also be used to trap substances in their inneraqueous compartment. The substance can be one that is only soluble inaqueous solutions. In one embodiment, a solution comprising alipopeptide and another amphipathic molecule can be sonicated to produceliposomes. In another embodiment, the lipopeptide alone can be sonicatedto produce liposomes. In a preferred embodiment, the liposome comprisesdaptomycin or a daptomycin-related lipopeptide such as A54145, alipopeptide disclosed in U.S. Pat. Nos. 4,537,717, 4,482,487, Re.32,311, Re. 32,310, 5,912,226, currently in reissue as U.S. Ser. No.09/547,357, U.S. Provisional Applications Nos. 60/170,943, 60/170,946 or60/170,945, filed Dec. 15, 1999, U.S. Provisional Application No.60/208,222, filed May 30, 2000, or A-21978 antibiotic in which then-decanoyl fatty acid side chain of daptomycin is replaced by ann-octanoyl, n-nonanoyl, n-undecanoyl, -dodecanoyl, n-tridecanoyl orn-tetradecanoyl fatty acid side chain. In a more preferred embodiment,the lipopeptide is daptomycin.

In another preferred embodiment, the liposomes comprise one or moretherapeutic substances in their inner aqueous compartments. In apreferred embodiment, the therapeutic substance is an antibiotic, ananti-inflammatory or an anti-fungal agent. In a more preferredembodiment, the therapeutic substance is an antibiotic or antifungalagent disclosed infra. In another preferred embodiment, the therapeuticsubstance is soluble in aqueous solution. In another preferredembodiment, a pharmaceutical composition comprises the liposome.

In a preferred embodiment, a pharmaceutical composition compriseslipopeptide micelles or lipopeptide micelle containing a therapeuticsubstance. The lipopeptide micelles may be spherical micelles, mixedmicelles or liposomes. Pharmaceutical compositions comprisinglipopeptide micelles may minimize local irritation upon injection orwhen administered intravenously. In one embodiment, the pharmaceuticalcomposition comprises a salt, a buffer to maintain a particular pH andmicelles. In a further embodiment, the pharmaceutical compositioncomprises one or more agents to stabilize the micelles and/or tostabilize the lipopeptide or other therapeutic substance. In oneembodiment, the pharmaceutical composition also comprises one or moretherapeutic substances. In a preferred embodiment, the therapeuticsubstance is an antibiotic, an anti-inflammatory or an antifungal agent.In a more preferred embodiment, the therapeutic substance is anantibiotic or antifungal agent disclosed infra. The therapeuticsubstance can be in addition to the therapeutic substance that isincorporated into the micelle, or can be the therapeutic agent that isincorporated into the micelle.

The pharmaceutical composition can be dried or lyophilized, in whichcase the micelles are formed when either an aqueous solution, such aswater or a buffer is added to the pharmaceutical composition. In apreferred embodiment, the pharmaceutical composition is lyophilized andcontains a physiological concentration of salt when reconstituted and abuffer that maintains a pH at which micelles spontaneously form at roomtemperature when sterile water or other buffer is added. In an even morepreferred embodiment, the pharmaceutical composition comprisesdaptomycin or related lipopeptide, such as A54145, thedaptomycin-related lipopeptides disclosed supra, or an A-21978antibiotic in which the n-decanoyl fatty acid side chain of daptomycinis replaced by an n-octanoyl, n-nonanoyl, n-undecanoyl, n-dodecanoyl,n-tridecanoyl or n-tetradecanoyl fatty acid side chain. In an even morepreferred embodiment, the lipopeptide is daptomycin. In anotherembodiment, the pharmaceutical composition is aqueous. This is preferredwhen liposomes are used. In a preferred embodiment, the pharmaceuticalcomposition comprises a stabilizing agent for the liposomes.

In another aspect of the invention, the micellar solution is isolatedand/or purified. In one embodiment, micelles are isolated from smallersubstituents by ultrafiltration. The choice of ultrafiltration membranewill be based upon the size of the micelle. In general, a 10,000 NMW or30,000 NMW membrane will be sufficient to retain micelles whilepermitting smaller substituents, such as contaminants to flow through.In another embodiment, micelles can be isolated and/or purified bydialysis, density gradient centrifugation or size exclusionchromatography. These methods are well-known in the art. In oneembodiment, the micelles are more than 30% pure, where purity ismeasured as the weight of the micelles compared to the weight ofmonomeric forms of the lipopeptide or of other molecules. In a preferredembodiment, the micelles are more than 50%, 60%, 70%, 80%, 90% or 95%pure.

In another aspect of the invention, the ability to form lipopeptidemicelles and then to disassociate them by altering temperature, pH,electrolyte concentration and/or lipopeptide concentration provides amethod for purifying lipopeptides. In one embodiment, the methodcomprises purifying lipopeptides from low molecular weight contaminantsby subjecting lipopeptides to conditions in which the lipopeptides formmicelles and then separating the micelles from the contaminants by asize selection technique, such as ultrafiltration or size exclusionchromatography. In another embodiment of the invention, the methodcomprises concentrating lipopeptides by subjecting lipopeptides toconditions in which the lipopeptides form micelles and thenconcentrating them by a size selection technique. In a more preferredembodiment, the method comprises both purification and concentration asa single step.

In another embodiment of the invention, the method comprises purifying alipopeptide from high molecular weight contaminants, including pyrogens(e.g., lipopolysaccharide), by subjecting the lipopeptide to conditionsunder which the lipopeptide is monomeric and then separating themonomeric lipopeptide solution from the high molecular weightcontaminants by a size separation technique. In a preferred embodiment,the size separation technique is ultrafiltration, as discussed supra. Inanother preferred embodiment, the lipopeptide is daptomycin or relatedlipopeptide, such as A54145, the daptomycin-related lipopeptidesdisclosed supra, or an A-21978 antibiotic in which the n-decanoyl fattyacid side chain of daptomycin is replaced by an n-octanoyl, n-nonanoyl,n-undecanoyl, n-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acidside chain. In an even more preferred embodiment, the lipopeptide isdaptomycin.

A preferred embodiment of the process chromatography method usingmicelles to purify daptomycin is described below:

Streptomyces roseosporus is fermented with a feed of n-decanoic acid asdescribed supra. After fermentation, the extracellular solution isclarified as described supra.

The clarified preparation is then applied to an anion exchange resin,such as FP-DA 13, as described supra. Daptomycin is eluted from thecolumn with one to three column volumes of an elevated salt buffercontaining 300 to 500 mM NaCl.

The eluted daptomycin preparation is adjusted to a pH of 2.5 to 5.0using an acid. In a preferred embodiment, the acid is dilute phosphoricacid. At pH 2.5 to 4.7, 300 to 500 mM NaCl and a temperature of 2-15°C., the daptomycin forms a micelle.

The daptomycin preparation is filtered on a 10,000 to 30,000 NMWultrafiltration membrane. During ultrafiltration, the daptomycinpreparation is washed with a buffer containing 30 mM sodium acetate pH3.5 and at temperatures of up to 15° C. The initial salt concentrationis 300 mM NaCl due to the elution conditions, but the salt concentrationdecreases as washing continues. Because daptomycin is in micellar form,it is retained on the filter while impurities smaller than the 10,000 to30,000 (depending upon the filter used), pass through the filter. Thedaptomycin preparation obtained is approximately 85-90% pure.

As an optional step, the daptomycin preparation may be diluted and itspH raised to 6.5 in order to convert the daptomycin to a monomericstate. The daptomycin preparation is then be passed through a 10,000 NMWultrafiltration membrane. This optional step decreases pyrogen contentsignificantly.

Methods for Analyzing Daptomycin Purity

Another embodiment of the invention provides analytical methods formeasuring the purity of daptomycin.

In the prior art, many of the contaminants that co-purified withdaptomycin were unresolved or unidentified because the ability tovisualize and measure impurities was limited by the analytical methodsand equipment available. See, e.g., U.S. Pat. No. 4,874,843 and Kirschet al. The development of more sensitive analytical HPLC systems andtechniques permits the resolution of a number of contaminants that existin daptomycin batches prepared by prior art methods. The higherresolution HPLC methods demonstrate that daptomycin as purified by priorart methods is contaminated with previously identified impurities, suchas anhydro-daptomycin and β-isomer, and other, previously unknowncontaminants that co-purify with daptomycin (and co-elute under thepreviously established HPLC detection conditions) during the practice ofprior art methods. Identification of these contaminants now permits thedevelopment of methods designed to eliminate these contaminants.

As discussed above, anhydro-daptomycin and the β-isomer were previouslydescribed as impurities that persistently and consistently occurredduring preparation of daptomycin. Using the HPLC analyses describedhere, an additional approximately twelve impurities produced during theproduction of daptomycin were distinguished, some of which hadpreviously not been identified. These impurities were not removed afterpurification by the method disclosed in U.S. Pat. No. 4,874,843. Atleast ten of these compounds have been identified (see, e.g., FIGS.2-11). Furthermore, at least six of these compounds are not the directresult of the reaction that produces anhydro-daptomycin and the β-isomerform of daptomycin, but rather are compounds produced by other,unrelated, processes that occur during the fermentation or purificationof daptomycin. The method of the instant invention, described below,also significantly reduces the levels of a number of these impurities(see Examples).

Any method known in the art may be used to measure the amount of othercompounds in a daptomycin preparation. Methods for identifyingdaptomycin contaminants include, without limitation, mass spectroscopy,infrared spectroscopy, capillary electrophoresis and nuclear magneticresonance spectroscopy. A preferred method for measuring the amount ofother compounds in a daptomycin preparation is HPLC.

Two methods were used to measure daptomycin impurities in the instantinvention. The first method is a slightly lower resolution method thanthe second method. In both methods, a Shimadzu or HP HPLC System with PENelson's Turbochrom Software Version 4.1 is used. The “first” resolutionmethod is summarized in Table 1 and the “second” resolution method issummarized in Table 2:

TABLE 1 1. Solvent Delivery System: Mode: Isocratic pumping Flow rate:1.5 mL/min Run time: 30 minutes 2. Solvent A: 34% acetonitrile in 0.5%NH₄H₂PO₄ at pH 4.5 Solvent B: 20% acetonitrile in 0.5% NH₄H₂PO₄ at pH4.5 The target condition is to retain daptomycin at 15.0 ± 0.5 minutes.Solvent B may be used together with solvent A to adjust the HPLC mobilephase conditions to achieve the desired retention time. 3. Autosamplercooler: 5 (4 to 6)° C. 4. Injection volume: 5 μL to 75 μL (20 uL normal)5. Column: IB-SIL (Phenomenex), C-8, 5μ, 4.6 mm × 250 mm (or equivalent)6. Pre-column: IB-SIL (Phenomenex), C-8, 5μ, 4.6 mm × 30 mm (orequivalent) 7. Detection wavelength: 214 nm 8. Column Temperature:ambient 9. Integration: A computer system or integrator capable ofmeasuring peak area.

TABLE 2 1. Solvent Delivery System: Mode: Isocratic pumping Flow rate:1.5 mL/min Run time: 75 minutes 2. Solvent A: 20% acetonitrile in 0.45%NH₄H₂PO₄ at pH 3.25 Solvent B: 50% acetonitrile in 0.45% NH₄H₂PO₄ at pH3.25 The target condition is approximately 35% acetonitrile in 0.45%NH₄H₂PO₄ at pH 3.25 (50% Solvent B) to retain daptomycin at 36.0 ± 1.5minutes; however, the solvent ratio will be used to adjust the HPLCmobile phase composition to achieve the desired retention time. 3.Autosampler cooler: 5 (4 to 6)° C. 4. Injection volume: 5 μL to 75 μL(20 μL normal) 5. Column: IB-SIL (Phenomenex), C-8, 5μ, 4.6 mm × 250 mm(or equivalent) 6. Pre-column: IB-SIL (Phenomenex), C-8, 5μ, 4.6 mm × 30mm (or equivalent) 7. Detection wavelength: 214 nm 8. ColumnTemperature: 25 (22 to 28)° C. 9. Integration: A computer system orintegrator capable of measuring peak area.Purified Lipopeptides, Pharmaceutical Compositions and Methods of UseThereof

Another object of the instant invention is to provide purifiedlipopeptides, as well as salts, esters, amides, ethers and protectedforms thereof, as well as pharmaceutical formulations comprisingpurified lipopeptides or its salts. In a preferred embodiment, thelipopeptide is daptomycin or a daptomycin-related lipopeptide, asdescribed supra. A further object of the instant invention is to providepharmaceutical compositions comprising lipopeptide micelles. In apreferred embodiment, the lipopeptide micelles are micelles comprisingdaptomycin or one or more daptomycin-related lipopeptides. All referenceherein to lipopeptide micelles refers not only to all lipopeptidemicelles, but specifically contemplates daptomycin, or relatedlipopeptide, such as A54145, the daptomycin-related lipopeptidesdisclosed supra, or an A-21978 antibiotic in which the n-decanoyl fattyacid side chain of daptomycin is replaced by an n-octanoyl, n-nonanoyl,n-undecanoyl, n-dodecanoyl, n-tridecanoyl or n-tetradecanoyl fatty acidside chain. Further, all references herein to lipopeptide micellesspecifically contemplates spherical micelles, mixed micelles andliposomes, as discussed supra.

Purified lipopeptides, pharmaceutically acceptable salts thereof, orlipopeptide micelles can be formulated for oral, intravenous,intramuscular, subcutaneous, aerosol, topical or parenteraladministration for the therapeutic or prophylactic treatment ofdiseases, particularly bacterial infections. In a preferred embodiment,the purified lipopeptide is purified daptomycin or a daptomycin-relatedlipopeptide. Reference herein to “purified daptomycin,” “purifieddaptomycin-related lipopeptide” or “purified lipopeptide” includespharmaceutically acceptable salts thereof. Daptomycin,daptomycin-related lipopeptide or other lipopeptide micelles can beformulated using any pharmaceutically acceptable carrier or excipientthat is compatible with daptomycin or with the lipopeptide of interest.See, e.g., Handbook of Pharmaceutical Additives: An International Guideto More than 6000 Products by Trade Name, Chemical, Function, andManufacturer, Ashgate Publishing Co., eds., M. Ash and I. Ash, 1996; TheMerck Index: An Encyclopedia of Chemicals, Drugs and Biologicals, ed. S.Budavari, annual; Remington's Pharmaceutical Sciences, Mack PublishingCompany, Easton, Pa.; Martindale: The Complete Drug Reference, ed. K.Parfitt, 1999; and Goodman & Gilman's The Pharmaceutical Basis ofTherapeutics, Pergamon Press, New York, N.Y., ed. L. S. Goodman et al.;the contents of which are incorporated herein by reference, for ageneral description of the methods for administering variousantimicrobial agents for human therapy. Purified daptomycin,daptomycin-related lipopeptide or other lipopeptide micelles of thisinvention can be mixed with conventional pharmaceutical carriers andexcipients and used in the form of tablets, capsules, elixirs,suspensions, syrups, wafers, creams and the like. Daptomycin,daptomycin-related lipopeptide or other lipopeptide micelles may bemixed with other therapeutic agents and antibiotics, such as discussedherein. The compositions comprising a compound of this invention willcontain from about 0.1 to about 90% by weight of the active compound,and more generally from about 10 to about 30%.

The compositions of the invention can be delivered using controlled(e.g., capsules) or sustained release delivery systems (e.g.,bioerodable matrices). Exemplary delayed release delivery systems fordrug delivery that are suitable for administration of the compositionsof the invention are described in U.S. Pat. No. 4,452,775 (issued toKent), U.S. Pat. No. 5,239,660 (issued to Leonard), U.S. Pat. No.3,854,480 (issued to Zaffaroni).

The compositions may contain common carriers and excipients, such ascorn starch or gelatin, lactose, sucrose, microcrystalline cellulose,kaolin, mannitol, dicalcium phosphate, sodium chloride and alginic acid.The compositions may contain croscarmellose sodium, microcrystallinecellulose, corn starch, sodium starch glycolate and alginic acid.

Tablet binders that can be included are acacia, methylcellulose, sodiumcarboxymethylcellulose, polyvinylpyrrolidone (Povidone), hydroxypropylmethylcellulose, sucrose, starch and ethylcellulose.

Lubricants that can be used include magnesium stearate or other metallicstearates, stearic acid, silicone fluid, talc, waxes, oils and colloidalsilica.

Flavoring agents such as peppermint, oil of wintergreen, cherryflavoring or the like can also be used. It may also be desirable to adda coloring agent to make the dosage form more aesthetic in appearance orto help identify the product.

For oral use, solid formulations such as tablets and capsules areparticularly useful. Sustained release or enterically coatedpreparations may also be devised. For pediatric and geriatricapplications, suspensions, syrups and chewable tablets are especiallysuitable. For oral administration, the pharmaceutical compositions arein the form of, for example, a tablet, capsule, suspension or liquid.The pharmaceutical composition is preferably made in the form of adosage unit containing a therapeutically-effective amount of the activeingredient. Examples of such dosage units are tablets and capsules. Fortherapeutic purposes, the tablets and capsules which can contain, inaddition to the active ingredient, conventional carriers such as bindingagents, for example, acacia gum, gelatin, polyvinylpyrrolidone,sorbitol, or tragacanth; fillers, for example, calcium phosphate,glycine, lactose, maize-starch, sorbitol, or sucrose; lubricants, forexample, magnesium stearate, polyethylene glycol, silica, or talc;disintegrants, for example, potato starch, flavoring or coloring agents,or acceptable wetting agents. Oral liquid preparations generally are inthe form of aqueous or oily solutions, suspensions, emulsions, syrups orelixirs may contain conventional additives such as suspending agents,emulsifying agents, non-aqueous agents, preservatives, coloring agentsand flavoring agents. Oral liquid preparations may comprise lipopeptidemicelles or monomeric forms of the lipopeptide. Examples of additivesfor liquid preparations include acacia, almond oil, ethyl alcohol,fractionated coconut oil, gelatin, glucose syrup, glycerin, hydrogenatededible fats, lecithin, methyl cellulose, methyl or propylpara-hydroxybenzoate, propylene glycol, sorbitol, or sorbic acid.

For intravenous (IV) use, a water soluble form of daptomycin,daptomycin-related lipopeptide or other lipopeptide can be dissolved inany of the commonly used intravenous fluids and administered byinfusion. For lipopeptide micelles, the lipopeptide is dissolved in anintravenous formulation under conditions in which the lipopeptide ispresent at a concentration above its cmc. One having ordinary skill inthe art may vary the pH, temperature or salt concentration following theteachings of this invention to obtain an intravenous solution comprisinglipopeptide micelles. Further, one may sonicate the lipopeptide solutionin order to obtain lipopeptide liposomes. Intravenous formulations mayinclude carriers, excipients or stabilizers including, withoutlimitation, calcium, human serum albumin, citrate, acetate, calciumchloride, carbonate, and other salts. Intravenous fluids include,without limitation, physiological saline or Ringer's solution.Daptomycin or daptomycin-related lipopeptide also may be placed ininjectors, cannulae, catheters and lines.

Formulations for parenteral administration can be in the form of aqueousor non-aqueous isotonic sterile injection solutions or suspensions.These solutions or suspensions can be prepared from sterile powders orgranules having one or more of the carriers mentioned for use in theformulations for oral administration. Lipopeptide micelles may beparticularly desirable for parenteral administration. The compounds canbe dissolved in polyethylene glycol, propylene glycol, ethanol, cornoil, benzyl alcohol, sodium chloride, and/or various buffers. Forintramuscular preparations, a sterile formulation of a lipopeptidecompound or a suitable soluble salt form of the compound, for examplethe hydrochloride salt, can be dissolved and administered in apharmaceutical diluent such as Water-for-Injection (WFI), physiologicalsaline or 5% glucose.

Lipopeptide micelles may be particularly desirable for parenteraladministration because they are likely to cause no local irritation atthe site of injection. Without wishing to be bound by any theory, it islikely that lipopeptide micelles will cause less local irritation thanmonomeric lipopeptides because the lipid tails, which might causeirritation upon injection, will be sequestered in the interior of themicelle, while the peptide nucleus, which is less likely to cause localirritation than the lipid tail, will be exposed to the tissue.Lipopeptide micelles may be prepared for intramuscular and parenteralpreparations by following the teachings of this invention to obtain apreparation comprising lipopeptide micelles. Further, one may sonicatethe lipopeptide solution in order to obtain lipopeptide liposomes. Asuitable insoluble form of the compound also may be prepared andadministered as a suspension in an aqueous base or a pharmaceuticallyacceptable oil base, e.g., an ester of a long chain fatty acid such asethyl oleate.

Injectable depot forms may be made by forming microencapsulated matricesof the compound in biodegradable polymers such aspolylactide-polyglycolide. Depending upon the ratio of drug to polymerand the nature of the particular polymer employed, the rate of drugrelease can be controlled. Examples of other biodegradable polymersinclude poly(orthoesters) and poly(anhydrides). Depot injectableformulations are also prepared by entrapping the drug in microemulsionsthat are compatible with body tissues.

For topical use the compounds and micelles of the present invention canalso be prepared in suitable forms to be applied to the skin, or mucusmembranes of the nose and throat, and can take the form of creams,ointments, liquid sprays or inhalants, lozenges, or throat paints. Suchtopical formulations further can include chemical compounds such asdimethylsulfoxide (DMSO) to facilitate surface penetration of the activeingredient. For topical preparations, a sterile formulation ofdaptomycin, daptomycin-related lipopeptide, suitable salt forms thereof,or a lipopeptide micelle may be administered in a cream, ointment, sprayor other topical dressing. Topical preparations may also be in the formof bandages that have been impregnated with purified daptomycin,daptomycin-related lipopeptide or a lipopeptide micelle composition.

For application to the eyes or ears, the compounds of the presentinvention can be presented in liquid or semi-liquid form formulated inhydrophobic or hydrophilic bases as ointments, creams, lotions, paintsor powders.

For rectal administration the compounds of the present invention can beadministered in the form of suppositories admixed with conventionalcarriers such as cocoa butter, wax or other glyceride.

For aerosol preparations, a sterile formulation of purified daptomycinor a daptomycin-related lipopeptide or salt form of the compound may beused in inhalers, such as metered dose inhalers, and nebulizers. Asterile formulation of a lipopeptide micelle may also be used foraerosol preparation. Aerosolized forms may be especially useful fortreating respiratory infections, such as pneumonia and sinus-basedinfections.

Alternatively, the compounds of the present invention can be in powderform for reconstitution in the appropriate pharmaceutically acceptablecarrier at the time of delivery. If the powder form is to bereconstituted as lipopeptide micelles, the powder may comprise a bufferand/or salt such that reconstitution with a particular quantity ofsterile water or saline will cause the lipopeptide to form micelles.Alternatively, the powder form may contain instructions regarding thequantity and type of pharmaceutically acceptable carrier is to be usedto reconstitute the lipopeptide in order to obtain micelles. In anotherembodiment, the unit dosage form of the compound can be a solution ofthe compound, a salt thereof, or a lipopeptide micelle in a suitablediluent in sterile, hermetically sealed ampules. The concentration ofthe compound in the unit dosage may vary, e.g. from about 1 percent toabout 50 percent, depending on the compound used and its solubility andthe dose desired by the physician. If the compositions contain dosageunits, each dosage unit preferably contains from 50-500 mg of the activematerial. For adult human treatment, the dosage employed preferablyranges from 100 mg to 3 g, per day, depending on the route and frequencyof administration.

In a further aspect, this invention provides a method for treating aninfection, especially those caused by gram-positive bacteria, in humansand other animals. The term “treating” is used to denote both theprevention of an infection and the control of an established infectionafter the host animal has become infected. An established infection maybe one that is acute or chronic. The method comprises administering tothe human or other animal an effective dose of a compound of thisinvention. An effective dose is generally between about 0.1 and about 25mg/kg purified daptomycin, daptomycin-related lipopeptide orpharmaceutically acceptable salts thereof. The daptomycin ordaptomycin-related lipopeptide may be monomeric or may be part of alipopeptide micelle. A preferred dose is from about 1 to about 25 mg/kgof purified daptomycin or daptomycin-related lipopeptide orpharmaceutically acceptable salts thereof. A more preferred dose is fromabout 1 to 12 mg/kg purified daptomycin or a pharmaceutically acceptablesalt thereof.

In one embodiment, the invention provides a method for treating aninfection, especially those caused by gram-positive bacteria, in asubject with a therapeutically-effective amount of daptomycin or otherantibacterial lipopeptide. The daptomycin or antibacterial lipopeptidemay be monomeric or in a lipopeptide micelle. Exemplary procedures fordelivering an antibacterial agent are described in U.S. Pat. No.5,041,567, issued to Rogers and in PCT patent application numberEP94/02552 (publication no. WO 95/05384), the entire contents of whichdocuments are incorporated in their entirety herein by reference. Asused herein the phrase “therapeutically-effective amount” means anamount of daptomycin or antibacterial lipopeptide according to thepresent invention that prevents the onset, alleviates the symptoms, orstops the progression of a bacterial infection. The term “treating” isdefined as administering, to a subject, a therapeutically-effectiveamount of a compound of the invention, both to prevent the occurrence ofan infection and to control or eliminate an infection. The term“subject”, as described herein, is defined as a mammal, a plant or acell culture. In a preferred embodiment, a subject is a human or otheranimal patient in need of lipopeptide compound treatment.

The lipopeptide antibiotic compound can be administered as a singledaily dose or in multiple doses per day. The treatment regime mayrequire administration over extended periods of time, e.g., for severaldays or for from two to four weeks. The amount per administered dose orthe total amount administered will depend on such factors as the natureand severity of the infection, the age and general health of thepatient, the tolerance of the patient to the antibiotic and themicroorganism or microorganisms involved in the infection. A method ofadministration is disclosed in U.S. Ser. No. 09/406,568, filed Sep. 24,1999, herein incorporated by reference, which claims the benefit of U.S.Provisional Application Nos. 60/101,828, filed Sep. 25, 1998, and60/125,750, filed Mar. 24, 1999.

The methods of the present invention comprise administering purifieddaptomycin or other lipopeptide antibiotic, or pharmaceuticalcompositions thereof to a patient in need thereof in an amount that isefficacious in reducing or eliminating the gram-positive bacterialinfection. The daptomycin or lipopeptide antibiotic may be eithermonomeric or may be present in a lipopeptide micelle. The antibiotic maybe administered orally, parenterally, by inhalation, topically,rectally, nasally, buccally, vaginally, or by an implanted reservoir,external pump or catheter. The antibiotic may be prepared for opthalmicor aerosolized uses. Purified daptomycin, lipopeptide antibiotic, orpharmaceutical compositions thereof also may be directly injected oradministered into an abscess, ventricle or joint. Parenteraladministration includes subcutaneous, intravenous, intramuscular,intra-articular, intra-synovial, cisternal, intrathecal, intrahepatic,intralesional and intracranial injection or infusion. In a preferredembodiment, daptomycin or other lipopeptide is administeredintravenously, subcutaneously or orally.

The method of the instant invention may be used to treat a patienthaving a bacterial infection in which the infection is caused orexacerbated by any type of gram-positive bacteria. In a preferredembodiment, purified daptomycin, daptomycin-related lipopeptide, otherlipopeptide or pharmaceutical compositions thereof are administered to apatient according to the methods of this invention. In another preferredembodiment, the bacterial infection may be caused or exacerbated bybacteria including, but not limited to, methicillin-susceptible andmethicillin-resistant staphylococci (including Staphylococcus aureus,Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcushominis, Staphylococcus saprophyticus, and coagulase-negativestaphylococci), glycopeptide intermediary-susceptible Staphylococcusaureus (GISA), penicillin-susceptible and penicillin-resistantstreptococci (including Streptococcus pneumoniae, Streptococcuspyogenes, Streptococcus agalactiae, Streptococcus avium, Streptococcusbovis, Streptococcus lactis, Streptococcus sangius and StreptococciGroup C, Streptococci Group G and viridans streptococci), enterococci(including vancomycin-susceptible and vancomycin-resistant strains suchas Enterococcus faecalis and Enterococcus faecium), Clostridiumdifficile, Clostridium clostridiiforme, Clostridium innocuum,Clostridium perfringens, Clostridium ramosum, Haemophilus influenzae,Listeria monocytogenes, Corynebacterium jeikeium, Bifidobacterium spp.,Eubacterium aerofaciens, Eubacterium lentum, Lactobacillus acidophilus,Lactobacillus casei, Lactobacilllus plantarum, Lactococcus spp.,Leuconostoc spp., Pediococcus, Peptostreptococcus anaerobius,Peptostreptococcus asaccarolyticus, Peptostreptococcus magnus,Peptostreptococcus micros, Peptostreptococcus prevotii,Peptostreptococcus productus, Propionibacterium acnes, and Actinomycesspp.

The antibacterial activity of daptomycin against classically “resistant”strains is comparable to that against classically “susceptible” strainsin in vitro experiments. In addition, the minimum inhibitoryconcentration (MIC) value for daptomycin against susceptible strains istypically 4-fold lower than that of vancomycin. Thus, in a preferredembodiment, purified daptomycin, daptomycin-related lipopeptideantibiotic, or pharmaceutical compositions thereof are administeredaccording to the methods of this invention to a patient who exhibits abacterial infection that is resistant to other antibiotics, includingvancomycin. In addition, unlike glycopeptide antibiotics, daptomycinexhibits rapid, concentration-dependent bactericidal activity againstgram-positive organisms. Thus, in a preferred embodiment, purifieddaptomycin, lipopeptide antibiotic, or pharmaceutical compositionsthereof are administered according to the methods of this invention to apatient in need of rapidly acting antibiotic therapy.

The method of the instant invention may be used for a gram-positivebacterial infection of any organ or tissue in the body. These organs ortissue include, without limitation, skeletal muscle, skin, bloodstream,kidneys, heart, lung and bone. The method of the invention may be usedto treat, without limitation, skin and soft tissue infections,bacteremia and urinary tract infections. The method of the invention maybe used to treat community acquired respiratory infections, including,without limitation, otitis media, sinusitis, chronic bronchitis andpneumonia, including pneumonia caused by drug-resistant Streptoococcuspneumoniae or Haemophilus influenzae. The method of the invention alsomay be used to treat mixed infections that comprise different types ofgram-positive bacteria, or which comprise both gram-positive andgram-negative bacteria, including aerobic, caprophilic or anaerobicbacteria. These types of infections include intra-abdominal infectionsand obstetrical/gynecological infections. The methods of the inventionmay be used in step-down therapy for hospital infections, including,without limitation, pneumonia, intra-abdominal sepsis, skin and softtissue infections and bone and joint infections. The method of theinvention also may be used to treat an infection including, withoutlimitation, endocarditis, nephritis, septic arthritis and osteomyelitis.In a preferred embodiment, any of the above-described diseases may betreated using purified daptomycin, lipopeptide antibiotic, orpharmaceutical compositions thereof. Further, the diseases may betreated using daptomycin or lipopeptide antibiotic in either a monomericor micellar form.

Daptomycin, daptomycin-related lipopeptide or other lipopeptide may alsobe administered in the diet or feed of a patient or animal. Ifadministered as part of a total dietary intake, the amount of daptomycinor other lipopeptide can be less than 1% by weight of the diet andpreferably no more than 0.5% by weight. The diet for animals can benormal foodstuffs to which daptomycin or lipopeptide can be added or itcan be added to a premix.

The method of the instant invention may also be practiced whileconcurrently administering one or more antifungal agents and/or one ormore antibiotics other than daptomycin or other lipopeptide antibiotic.Co-administration of an antifungal agent and an antibiotic other thandaptomycin or another lipopeptide antibiotic may be useful for mixedinfections such as those caused by different types of gram-positivebacteria, those caused by both gram-positive and gram-negative bacteria,or those that caused by both bacteria and fungus. Furthermore,daptomycin or other lipopeptide antibiotic may improve the toxicityprofile of one or more co-administered antibiotics. It has been shownthat administration of daptomycin and an aminoglycoside may amelioraterenal toxicity caused by the aminoglycoside. In a preferred embodiment,an antibiotic and/or antifungal agent may be administered concurrentlywith purified daptomycin, other lipopeptide antibiotic, or inpharmaceutical compositions comprising purified daptomycin or anotherlipopeptide antibiotic.

Co-administration of another therapeutic agent with daptomycin oranother lipopeptide antibiotic may be performed using daptomycin orlipopeptide antibiotic in either a monomeric or micellar form. Asdiscussed supra, spherical lipopeptide micelles can be used to helpsolubilize agents that exhibit low aqueous solubility. Further,lipopeptide liposomes can be used to trap agents that are soluble inaqueous media inside the vesicle of the liposomes. By following theteachings of the specification, one having ordinary skill in the artwould be able to make lipopeptide micelles comprising therapeuticagents, such as anti-inflammatory agents, anti-fungal agents and otherantibiotics.

Antibacterial agents and classes thereof that may be co-administeredwith daptomycin or other lipopeptide antibiotics include, withoutlimitation, penicillins and related drugs, carbapenems, cephalosporinsand related drugs, aminoglycosides, bacitracin, gramicidin, mupirocin,chloramphenicol, thiamphenicol, fusidate sodium, lincomycin,clindamycin, macrolides, novobiocin, polymyxins, rifamycins,spectinomycin, tetracyclines, vancomycin, teicoplanin, streptogramins,anti-folate agents including sulfonamides, trimethoprim and itscombinations and pyrimethamine, synthetic antibacterials includingnitrofurans, methenamine mandelate and methenamine hippurate,nitroimidazoles, quinolones, fluoroquinolones, isoniazid, ethambutol,pyrazinamide, para-aminosalicylic acid (PAS), cycloserine, capreomycin,ethionamide, prothionamide, thiacetazone, viomycin, eveminomycin,glycopeptide, glycylcylcline, ketolides, oxazolidinone; imipenen,amikacin, netilmicin, fosfomycin, gentamicin, ceftriaxone, Ziracin, LY333328, CL 331002, HMR 3647, Linezolid, Synercid, Aztreonam, andMetronidazole, Epiroprim, OCA-983, GV-143253, Sanfetrinem sodium,CS-834, Biapenem, A-99058.1, A-165600, A-179796, KA 159, Dynemicin A,DX8739, DU 6681; Cefluprenam, ER 35786, Cefoselis, Sanfetrinemcelexetil, HGP-31, Cefpirome, HMR-3647, RU-59863, Mersacidin, KP 736,Rifalazil; Kosan, AM 1732, MEN 10700, Lenapenem, BO 2502A, NE-1530, PR39, K130, OPC 20000, OPC 2045, Veneprim, PD 138312, PD 140248, CP111905, Sulopenem, ritipenam acoxyl, RO-65-5788, Cyclothialidine,Sch-40832, SEP-132613, micacocidin A, SB-275833, SR-15402, SUN A0026,TOC 39, carumonam, Cefozopran, Cefetamet pivoxil, and T 3811.

In a preferred embodiment, antibacterial agents that may beco-administered with daptomycin according to this invention include,without limitation, imipenen, amikacin, netilmicin, fosfomycin,gentamicin, ceftriaxone, teicoplanin, Ziracin, LY 333328, CL 331002, HMR3647, Linezolid, Synercid, Aztreonam, and Metronidazole.

Antifungal agents that may be co-administered with daptomycin or otherlipopeptide antibiotic include, without limitation, Caspofungen,Voriconazole, Sertaconazole, IB-367, FK-463, LY-303366, Sch-56592,Sitafloxacin, DB-289 polyenes, such as Amphotericin, Nystatin,Primaricin; azoles, such as Fluconazole, Itraconazole, and Ketoconazole;allylamines, such as Naftifine and Terbinafine; and anti-metabolitessuch as Flucytosine. Other antifungal agents include without limitation,those disclosed in Fostel et al., Drug Discovery Today 5:25-32 (2000),herein incorporated by reference. Fostel et al. disclose antifungalcompounds including Corynecandin, Mer-WF3010, Fusacandins,Artrichitin/LL 15G256γ, Sordarins, Cispentacin, Azoxybacillin,Aureobasidin and Khafrefungin.

Daptomycin or other lipopeptide antibiotic, including daptomycin-relatedlipopeptides, may be administered according to this method until thebacterial infection is eradicated or reduced. In one embodiment,daptomycin or other lipopeptide is administered for a period of timefrom 3 days to 6 months. In a preferred embodiment, daptomycin or otherlipopeptide is administered for 7 to 56 days. In a more preferredembodiment, daptomycin or other lipopeptide is administered for 7 to 28days. In an even more preferred embodiment, daptomycin or otherlipopeptide is administered for 7 to 14 days. Daptomycin or otherlipopeptide may be administered for a longer or shorter time period ifit is so desired.

In order that this invention may be more fully understood, the followingexamples are set forth. These examples are for the purpose ofillustration only and are not to be construed as limiting the scope ofthe invention in any way.

EXAMPLE 1

A fermentation culture of S. roseosporus NRRL Strain 15998 is conductedin a controlled decanoic acid feed fermentation at levels that optimizethe production of the antibiotic while minimizing the production ofcontaminants. The residual decanoic acid feed is measured by gaschromatography and the target residual level is 10 ppm decanoic acidfrom the start of induction (approximately at hour 30) until harvest.Centrifugation of the culture and subsequent analysis of the clarifiedbroth are used to measure the production of daptomycin by HPLC. Theharvest titer is typically between 2.1 and 2.6 grams per liter offermentation broth.

The fermentation is harvested either by microfiltration using a Pall-Sepor by full commercial-scale centrifugation and depth filter. Theclarified broth is applied to an anion exchange resin, Mitsubishi FP-DA13, washed with 30 mM NaCl at pH 6.5 and eluted with 300 mM NaCl at pH6.0-6.5. Alternatively, the FP-DA 13 column is washed with 60 mM NaCl atpH 6.5 and eluted with 500 mM NaCl at pH 6.0-6.5. The eluate is appliedto a HIC resin, HP-20ss, washed with 30% acetonitrile, and eluted with35% acetonitrile at pH 4.0-5.0. Alternatively, the HIC resin is washedwith 45% isopropyl alcohol and eluted with 55-60% isopropyl alcohol. Theeluate is applied to FP-DA 13 resin and washed and eluted as before. Thefinal anion exchange step reduces solvent by one third or more. Reverseosmosis diafiltration and concentration at pH 1.5-2.5 is performed usingan 0.2 μm filter and the daptomycin preparation is frozen. A finalreverse osmosis diafiltration is conducted with Water-For-Injection(WFI) to wash daptomycin and adjust its concentration prior tosterile-filling. Vials or bulk quantities of daptomycin are thenlyophilized

EXAMPLE 2

Daptomycin was produced in a fermentation culture of S. roseosporus andpartially purified Daptomycin (9.9 Kg) was purified by microfiltrationfrom 5500 liters of fermentation broth by the method described in U.S.Pat. No. 4,885,243. The partially purified daptomycin was furtherpurified by the method described in U.S. Pat. No. 4,874,843, andresulted in a bulk daptomycin preparation with a purity of 91%. Thedaptomycin preparation contained fourteen impurities by HPLC analysis(see Example 10). The daptomycin preparation was applied to a Poros P150anion exchange resin (PE Biosystems) in Tris buffer pH 7.0 containing 6Murea and allowed to bind to the resin. The resin was washed with threecolumn volumes of buffer prior to initiation of a NaCl gradient in thesame buffer. Alternatively, the contaminants can be effectively removedfrom the column with a fixed salt level of 30 mM NaCl. The elution ofpurified daptomycin from the resin occurred at approximately 300 mM NaClduring a 0 to 1000 mM NaCl gradient. Daptomycin eluted from the columnwas greater than 99% pure as measured by the “first” HPLC method. Thepurified daptomycin contained only one detectable daptomycincontaminant. Anhydro-daptomycin and β-isomer were undetectable (lessthan 0.01% contamination). The level of the unidentified contaminant wasgreater than 0.1% and less than 0.5%.

EXAMPLE 3

A bulk daptomycin preparation with a purity of 91% was prepared asdescribed in Example 2. The product was applied to a Poros D50 anionexchange resin (PE Biosystems) in an acetate buffer pH 7.0 containing 6Murea. The Poros D50 resin was washed and eluted in the same manner asdescribed in Example 2. Daptomycin eluted from the column was 96.92%pure as measured by the “second” HPLC method. The product of thisinvention contained only two of the initial fourteen impurities (lessthan 0.5% contamination). Anhydro-daptomycin could not be detected inthe purified daptomycin preparation (less than 0.01% contamination andwith precise quantitation at less than 0.05%).

EXAMPLE 4

A fermentation broth containing daptomycin was produced as described inExample 2. The fermentation broth was clarified by microfiltration. Theclarified product was extracted with 20% n-butanol or iso-butanol at pH4.5 (one part butanol to four parts clarified solution). Re-extractionof the clarified solution was performed to achieve a yield of partiallypurified daptomycin of greater than 90% of the total daptomycin in theclarified solution. Daptomycin was recovered from the butanol phase bythe addition of a pH 6.5 aqueous buffer in a volume that is one-half ormore of the volume of butanol to extract daptomycin from the butanolphase into the aqueous phase. The butanol extraction step resulted in apartially purified daptomycin preparation that was purified 5-fold andconcentrated 10-fold relative to the clarified solution.

The aqueous daptomycin preparation was then purified by the methoddisclosed in U.S. Pat. No. 4,874,843, resulting in daptomycin that was91% pure. Daptomycin contained fourteen impurities. The product wasapplied to a Poros D50 resin in a Tris buffer at pH 7.0 containing 6Murea. The resin was washed with three bed volumes of Tris buffer at pH7.0 containing 6M urea prior to initiation of a NaCl gradient from 0 to1000 mM in the same buffer. Elution of purified daptomycin from theresin occurred at approximately 300 mM NaCl. Daptomycin was 98% pure asmeasured by the “second” HPLC method.

EXAMPLE 5

Daptomycin is fermented as described in Example 2. The 5500 litersfermentation broth contains 13 Kg daptomycin. The fermentation broth isdirectly extracted with 20% n-butanol at pH 4.5, which partitionsdaptomycin into the butanol. Re-extractions of the fermentation brothwith butanol are performed to achieve a yield of greater than 90% of thetotal daptomycin in the fermentation broth. The butanol phase isextracted with an aqueous acetate buffer at pH 6.5, resulting indaptomycin that is purified 5-fold (35%) and concentrated 10-foldrelative to the fermentation broth. The aqueous daptomycin ismicrofiltered by the method described in U.S. Pat. No. 4,885,243, thenpurified by the method of U.S. Pat. No. 4,874,843. This method resultsin daptomycin with a purity of approximately 91%. Daptomycin contains 14impurities by the HPLC method used at the time of the prior art. Theproduct is applied to a Poros D50 resin column in a acetate buffer at pH7.0 containing 6M urea. Washing and elution of the resin is performed asindicated in Example 2. The product of the chromatographic step isapproximately 98% to 99% pure as measured by the second HPLC method.

EXAMPLE 6

Daptomycin was produced in a fermentation culture of S. roseosporusexcept a reduced residual decanoic acid feed was used in order toimprove the quality of the fermentation to about 10% purity whenclarified by microfiltration or centrifugation. The decanoic acid levelwas monitored and periodically adjusted to maintain the residualdecanoic acid levels at less than 50 ppm and preferably between 1 and 10ppm during fermentation. The fermentation broth was microfiltered by themethod described in U.S. Pat. No. 4,885,243 to produce 12.1 Kg partiallypurified daptomycin from 5500 liters of fermentation broth. Clarifiedfermentation broth was bound to the anion exchanger, FP-DA 13(Mitsubishi) in acetate buffer at neutral pH, washed in acetate buffercontaining 30 mM NaCl, and subsequently eluted with acetate buffer at300 mM NaCl. This anion exchange step produced daptomycin with a purityof greater than 70%. This partially purified daptomycin was furtherpurified by the method of U.S. Pat. No. 4,874,843 with the modificationthat HP-20ss resin was used. Specifically, the partially purifieddaptomycin was loaded on HP-20ss in acetate buffer containing 10%acetonitrile, washed with acetate buffer containing 30% acetonitrile andeluted with 40% acetonitrile in acetate buffer, resulting in daptomycinwith a purity of about 94 to 96% as measured by the “second” HPLCmethod. The product is subjected to modified buffer enhanced anionexchange chromatography using Poros D50 resin as described in Example 5.Daptomycin is greater than 99% pure and contains only two of thefourteen impurities produced by methods described in the prior art.

EXAMPLE 7

A daptomycin preparation with a purity of 93% was prepared as describedin Example 2. The product was applied to a Poros P150 resin (PEBiosystems) in an acetate buffer pH 6.0 containing 2M urea. The PorosP150 resin was washed with three column volumes of the buffer.Daptomycin was eluted from the resin using a 0 to 400 mM NaCl gradientin the acetate buffer pH 6.0 containing 2M urea. Daptomycin elutedbetween 150 and 300 mM NaCl. Daptomycin eluted from the column was 99.0to 99.5% pure as measured by the “first” HPLC method. Daptomycincontained trace amounts of four impurities that were less than 1% of thetotal of daptomycin. Anhydro-daptomycin could not be detected in thepurified daptomycin preparation (less than 0.02% contamination).

EXAMPLE 8

A daptomycin preparation with a purity of 93% was prepared as describedin Example 2. The product was applied to a Poros P150 resin (PEBiosystems) in an acetate buffer pH 6.0 containing 2M urea. The columnwas washed with six column volumes of 60 mM NaCl in acetate buffer pH6.0 containing 2M urea (the “wash buffer”). The wash buffer may varyfrom 50-75 mM NaCl. The wash removes virtually all anhydro-daptomycin.Daptomycin is eluted with sixteen column volumes of 250 mM NaCl inacetate buffer pH 6.0 containing 2M urea. Daptomycin is 98.5 to 99.5%pure as measured by the “first” HPLC method.

EXAMPLE 9

A daptomycin preparation as described in Example 2 was prepared using amethod that significantly reduced the concentration of solvent requiredto perform the HP-20ss chromatography. Unexpectedly, the solvent forelution of daptomycin, 40% acetonitrile or 55-60% isopropyl alcohol, wasreduced to 12% and 25%, respectively, when HP-20ss chromatography wasconducted at neutral pH rather than acidic pH as described in U.S. Pat.No. 4,874,843. In a preferred embodiment, pH shifts can be used torecycle the HP-20ss resin without solvent removal.

After elution from a FP-DA13 column at pH 6.5-7.0, daptomycin is loadedon an equilibrated HP-20ss column, such as one that has beenequilibrated in 60 mM acetate, pH 6.6. The column is washed with five toeight column bed volumes (CBV) wash buffer. An exemplary wash buffer is5% isopropyl alcohol/60 mM acetate, pH 6.6. Daptomycin is eluted fromthe column with elution buffer. An exemplary elution buffer is two tothree CBV 25% isopropyl alcohol/60 mM acetate pH 6.6. The column isstripped with strip buffer. In one embodiment, the column is strippedwith one CBV 40% isopropyl alcohol/60 mM acetate pH 6.6-7.0. Thedaptomycin solution is adjusted to pH 3.5-4.0 and is reloaded on to theHP-20ss column in order to further enhance purity. In one embodiment,the daptomycin eluted from the HP-20ss column at pH 6.5 is adjusted topH 3.5 using 0.25M phosphoric acid. The daptomycin solution is reloadedon the previously stripped HP-20ss column that has been equilibrated in60 mM acetate, pH 3.5. The column is washed with a pH adjusting buffersuch that the pH is 6.5. An exemplary pH adjusting buffer is five toeight CBV 5% isopropyl alcohol/60 mM acetate, pH 6.6. The daptomycin iseluted with elution buffer and may be further purified by anion exchangeor other purification methods, if desired. The HP-20ss column isstripped with strip buffer and cleaned prior to reuse. An exemplarycleaning process includes washing with three CBV 0.5M NaOH, washing withone CBV water, and then washing with 0.25M phosphoric acid prior toequilibration. The column may be stored in 0.5M NaOH.

EXAMPLE 10

Bulk daptomycin prepared as described in Example 2 was characterized viasemi-preparative HPLC and characterized by liquid chromatography/massspectroscopy (LC/MS) using both positive and negative ion modes. Animpurity profile of the bulk daptomycin prior to chromatography on thePoros P150 anion exchange resin is shown in Table 3 and a chromatogramof the bulk daptomycin preparation is shown in FIG. 12.

TABLE 3 Impurity Retention Observed Cubist % of Total ID Time MW LillyID ID Area by HPLC 1  7.96 1638 LY212218 CB-131012 >0.5%, <1.0% 2  9.111638 CB-131011 <0.5%, >0.1% 3 11.54  745 LY213928 CB-131008 >0.5%, <1.0%4 12.28 1624 CB-131006 <0.5%, >0.1% 5 13.10 1618 Unknown-1 <0.5%, >0.1%6 14.43  587 LY213827 CB-130989 >0.5%, <1.0% 7 14.43 1606CB-131005 >0.5%, <1.0% 8 15.10 1620 LY213846 CB-131010 >1.0%, <4.0%Dapto- 16.68 1620 LY146032 CB-109187 >90% mycin 9 17.92  874 Unknown-2<0.5%, >0.1% 10 19.57 1810 Unknown-3 <0.5%, >0.1% 11 19.57 1635Unknown-4 <0.5%, >0.1% 12 20.93  859 CB-131009 <0.5%, >0.1% 13 23.111602 LY178480 CB-130952  >1.0, <4.0% 14 24.53 1634 LY109208 CB-131078<0.1 

Impurity 1 (CB-131012), which elutes at approximately 7.96 minutes, (MW:1638) is proposed to be a lactone hydrolysis product of daptomycin (FIG.4). The results seem to match LY212218 as previously identified by Lillyas a decyl ring opened derivative of daptomycin.

Impurity 2 (CB-131011), which elutes at approximately 9.11 minutes, (MW:1638) is also proposed to be a lactone hydrolysis product of theβ-isomer (FIG. 5).

Impurity 3 (CB-131008), which elutes at approximately 11.54 minutes,(MW: 745) is proposed to be a linear lipopeptide consisting of a fiveamino acid chain containing tryptophan, asparagine, aspartate, threonineand glycine with a decanoic acid chain (FIG. 6). This result seems tomatch LY213928 as previously identified by Lilly.

Impurity 4 (CB-131006), which elutes at approximately 12.28 minutes,(MW: 1624) is proposed to be an oxidative analog of daptomycin in whichthe amino acid tryptophan has been oxidized to kynuric acid (FIG. 7).

Impurity 5, which elutes at approximately 13.10 minutes, (MW: 1618) hasnot yet been assigned a structure.

Impurity 6 (CB-130989) and Impurity 7 (CB-131005) co-elute atapproximately 14.43 minutes. CB-130989 (MW: 587) seems to match LY213827a linear lipopeptide consisting of a three amino acid chain oftryptophan, asparagine and aspartate with a decanoic acid chain (FIG.8), as previously identified by Lilly. CB-131005 (MW:1606) correspondsto a daptomycin analog in which the decanoic acid lacks one methyl group(FIG. 9).

Impurity 8 (CB-131010), elutes at approximately 15.10 minutes, (MW:1620) matches LY213846 (β-isomer) as previously identified by Lilly(FIG. 2). Levels of β-isomer are greater than 1%.

Impurity 9, which elutes at approximately 17.92 minutes (MW: 874), hasnot yet been assigned a structure.

Impurity 10 and 11, which co-elute at approximately 19.57 minutes, havenot been assigned a structure.

Impurity 12 (CB-131009), which elutes at 20.93 minutes (MW: 859), isproposed to be a linear lipopeptide consisting of a six amino acid chainof tryptophan, asparagine, aspartate, threonine, glycine and ornithinewith a decanoic acid chain (FIG. 10).

Impurity 13 (CB-130952), which elutes at approximately 23.11 minutes(MW: 1602), is proposed to be anhydro-daptomycin (FIG. 3), and appearsto be the same as LY178480. Levels of anhydro-daptomycin are greaterthan 1%.

Impurity 14 (CB-131078), which elutes at approximately 24.53 minutes(MW: 1634), appears to be the same as LY109208, previously identified byLilly as a daptomycin analog containing an extra methyl group in thedecanoic acid chain (FIG. 11).

The bulk daptomycin may be purified on Poros P150 as described above inExamples 2 or 7-8 or may be purified on Poros D50 as described above inExamples 3-5. After purification on Poros P150 as described in Example2, a chromatogram (FIG. 13) shows that daptomycin purity is greater than99.0%, with β-isomer and anhydro-daptomycin below the level of detection(less than 0.05% of total). There is one unidentified impurity which ispresent in a quantity of greater than 0.1% but less than 0.5%.

EXAMPLE 11

A fermentation culture of S. roseosporus NRRL Strain 15998 is conductedin a controlled decanoic acid feed fermentation at levels that optimizethe production of the antibiotic while minimizing the production ofcontaminants. The residual decanoic acid feed is measured by gaschromatography and the target residual level is 10 ppm decanoic acidfrom the start of induction (approximately at hour 30) until harvest.Centrifugation of the culture and subsequent analysis of the clarifiedbroth are used to measure the production of daptomycin by HPLC. Theharvest titer is typically between 1.0 and 3.0 grams per liter offermentation broth.

The fermentation is harvested either by microfiltration using a Pall-Sepor by full commercial-scale centrifugation and depth filter. Theclarified broth is applied to an anion exchange resin, Mitsubishi FP-DA13, washed with 30 mM NaCl at pH 6.5 and eluted with 300 mM NaCl at pH6.0-6.5. Alternatively, the FP-DA 13 column is washed with 60 mM NaCl atpH 6.5 and eluted with 500 mM NaCl at pH 6.0-6.5. The pH is adjusted to3.0 to 4.8 and the temperature is adjusted to 2-15° C. Under theseconditions, daptomycin forms a micelle. The micellar daptomycin solutionis purified by washing the micellar preparation while it is retained ona ultrafilter using a 10,000 NMW filter (AG Technology Corp. UF hollowfiber or equivalent) in any configuration. The daptomycin micelles areretained by the filter, but a large number of impurities are eliminatedbecause they pass through the 10,000 NMW filter. Ultrafiltration ofdaptomycin micelles increases daptomycin purity from approximately 40%to 80% or greater.

The eluate is applied to a HIC resin, HP-20ss, washed with 30%acetonitrile, and eluted with 35% acetonitrile at pH 4.0-5.0.Alternatively, the HIC resin is washed with 20-30% isopropyl alcohol andeluted with 30-40% isopropyl alcohol at pH 3.5-6.5. Under theseconditions of increased solvent and a higher pH of 6.0-7.5, daptomycinreverts to a single, non-micelle state. The eluate is applied to FP-DA13 resin column and washed and eluted as before. The final anionexchange step reduces solvent by one third or more. Reverse osmosisdiafiltration and concentration at pH 1.5-2.5 is performed using an 0.2μm filter and the daptomycin preparation is frozen. A final reverseosmosis diafiltration is conducted with Water-For-Injection (WFI) towash daptomycin and adjust its concentration prior to sterile-filling.Vials or bulk quantities of daptomycin are then lyophilized.

EXAMPLE 12

Lyophilized daptomycin purified as described in any of theabove-described examples, such as that described in Example 11, isreconstituted in physiologic saline (approximately 140 mM NaCl) at a pHof 4.0-5.0. Under these conditions, daptomycin is present as a micelle,and can be used for injection or intravenous, parenteral, oral ortopical administration.

EXAMPLE 13

Daptomycin is produced by fermentation and clarified from the broth bymicrofiltration as described in Example 11. The clarified broth isapplied to an anion exchange resin, Mitsubishi FP-DA 13, washed with 30mM NaCl at pH 6.5 and eluted with 300 mM NaCl at pH 6.0-6.5 to give adaptomycin preparation that is approximately 40% pure. The eluate isadjusted to pH 3.5 with dilute phosphoric acid such that virtually allof the daptomycin forms micelles. The micelle preparation is loaded on a10,000 NMW ultrafiltration membrane. The daptomycin preparation iswashed with 30 mM sodium acetate pH 3.5 and at temperatures of up to 15°C. The reduction in volume and washing lowers the contamination level,which results in an 85% pure daptomycin preparation. The daptomycinpreparation can be further purified using any of the methods describedherein.

EXAMPLE 14

Daptomycin is produced by fermentation, clarified from the broth bymicrofiltration, and fractionated on the FP-DA 13 resin as described inExample 11. The eluate is adjusted to pH 3.5 with dilute phosphoric acidsuch that virtually all of the daptomycin forms micelles. The micellepreparation is loaded on a 10,000 NMW ultrafiltration membrane. Thedaptomycin preparation is washed with 30 mM sodium acetate pH 3.5 and attemperatures of up to 15° C. The reduction in volume and washing lowersthe contamination level, which results in an 80-90% pure daptomycinpreparation. The daptomycin preparation can be further purified usingany of the methods described herein.

EXAMPLE 15

Daptomycin is produced by fermentation and clarified from the brothusing microfiltration as described in Example 11. The preparation ispurified using hydrophobic interaction chromatography, as described inU.S. Pat. No. 4,874,843, herein incorporated by reference. In thismethod, repeated column chromatography on HP-20 and HP-20ss resin isused. Daptomycin purity is 93% with visible impurities on HPLCchromatographs and measurable pyrogen. The product is diluted in waterand its pH was adjusted to pH 6.5 with NaOH or the equivalent. Thedaptomycin preparation is filtered through a 10,000 NMW ultrafiltrationmembrane. Under these conditions, daptomycin is monomeric and passesthrough the ultrafiltration membrane. The resulting product remains 93%pure, but several impurities that had been present at 0.1-0.2% areremoved by the ultrafiltration membrane. In addition, pyrogen content isreduced to undetectable levels.

EXAMPLE 16

A daptomycin preparation of approximately 93% purity is prepared asdescribed in Example 15. The daptomycin preparation is converted to amicellar state by lowering the pH to 4.7 with HCl or equivalent andchilling the daptomycin preparation to 2-5° C. The product isconcentrated from 400 liters to three liters and to a finalconcentration of approximately 100 mg/ml by filtration on a 10,000 NMWultrafiltration membrane. Under these conditions, daptomycin is retainedby the membrane. This results in a large increase in daptomycinconcentration. The purity is approximately 93%.

EXAMPLE 17

A daptomycin preparation is prepared as described in Example 16. Vialsare filled with approximately 250 mg daptomycin and lyophilized Thedaptomycin is reconstituted in 50 ml of sterile 150 mM saline at a pH of4.0-5.0 for administration to a human or animal patient. The dose ofdaptomycin that is administered will depend upon the nature of theinfection, the age and weight of the patient, and the species of animal.At a pH of 4.0-5.0 in 150 mM saline, the daptomycin will be present in amicellar state, which is soluble and suitable for intravenous,intramuscular or parenteral injection. The formulation will minimize anylocal irritation due to the lipopeptide nature of daptomycin.

EXAMPLE 18

Daptomycin micelles were produced using daptomycin at a concentration of1.0 mg/mL in water at pH 4.0 at 25° C. The size of a daptomycin micellewas measured using a Zetasizer™ (Malvern Instruments, Model 3000 HS).The count rate of 36.3, the cell type was a capillary cell, thedetection angle (deg) was 90°, and the wavelength (nm) was 633. Resultsindicated that the diameter of the micelle was 54 A, which is abouttwice the diameter of a single monomeric daptomycin molecule. See FIG.18.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference. Although the foregoing invention has beendescribed in some detail by way of illustration and example for purposesof clarity of understanding, it will be readily apparent to those ofordinary skill in the art in light of the teachings of this inventionthat certain changes and modifications may be made thereto withoutdeparting from the spirit or scope of the appended claims.

We claim:
 1. A composition obtained by a process comprising the step offorming a daptomycin aggregate, the composition comprising daptomycin ofgreater than or about 93% purity relative to impurities 1-14 defined bypeaks 1-14 shown in FIG. 12 and having less than 4% ofanhydro-daptomycin and having less than 4% of β-isomer of daptomycin. 2.The composition according to claim 1 that is free of each of impurities1 to 14 defined by peaks 1-14 shown in FIG.
 12. 3. The compositionaccording to claim 1 that is essentially free of at least one ofimpurities 1 to 14 defined by peaks 1-14 shown in FIG.
 12. 4. Thecomposition of claim 1, wherein daptomycin purity is measured by HPLC.5. The composition according to claim 1 wherein the process comprisesthe steps of: i) providing a daptomycin solution under conditions inwhich the daptomycin is in a monomeric and nonmicellar state; ii)filtering the daptomycin solution under conditions in which thedaptomycin passes through the filter but pyrogens do not pass throughthe filter; iii) subjecting the daptomycin solution to conditionsforming a daptomycin aggregate; iv) filtering the daptomycin aggregateunder conditions in which the daptomycin aggregate is retained on thefilter; and v) collecting the daptomycin aggregate.
 6. The compositionaccording to claim 5, wherein the process further comprises the step oflyophilizing daptomycin.
 7. The composition of claim 1 comprisingdaptomycin having less than 1% of β-isomer of daptomycin.
 8. Thecomposition of claim 1, comprising daptomycin having greater than 93%purity.
 9. The composition of claim 1, comprising daptomycin having lessthan 1% of the lactone hydrolysis product of daptomycin.
 10. Thecomposition of claim 1, comprising daptomycin that is substantially freeof β-isomer of daptomycin.
 11. The composition of claim 10, comprisingdaptomycin of greater than 93% purity.
 12. The composition of claim 1,comprising daptomycin of at least 95% purity.
 13. The composition ofclaim 1, comprising daptomycin with a purity of about 94 to 96%.
 14. Thecomposition of claim 1, comprising daptomycin of at least 97% purity.15. The composition of claim 1, comprising lyophilized daptomycin havinggreater than 93% purity relative to impurities 1-14 defined by peaks1-14 shown in FIG. 12, and having less than 1% of the lactone hydrolysisproduct of daptomycin.
 16. The composition of claim 15, wherein thedaptomycin is substantially free of β-isomer of daptomycin.
 17. Apharmaceutical composition compatible with a pharmaceutically acceptablecarrier for the treatment of an infection of the blood, skin or softtissue, the composition comprising daptomycin obtained by a processcomprising the step of forming a daptomycin aggregate, the compositionhaving daptomycin with greater than or about 93% purity relative toimpurities 1-14 defined by peaks 1-14 shown in FIG.
 12. 18. Thepharmaceutical composition of claim 17, wherein the daptomycin hasgreater than 93% purity and less than 4% anhydro daptomycin.
 19. Thepharmaceutical composition of claim 17, wherein the pharmaceuticallyacceptable carrier is selected from the group consisting ofphysiological saline and Ringer's solution for reconstitution foradministration as a single daily dose to the subject.
 20. Thepharmaceutical composition of claim 17, wherein the pharmaceuticalcomposition is compatible with the pharmaceutically acceptable carrierfor the treatment of an infection of the blood, skin or soft tissue byadministration in a daily dose of 1 to 12 mg/kg of the daptomycin in areconstituted solution of the composition in the pharmaceuticallyacceptable carrier.
 21. The pharmaceutical composition of claim 20,wherein a) the pharmaceutically acceptable carrier is selected from thegroup consisting of physiological saline and Ringer's solution forintravenous administration as a single daily dose to the subject; b) thedaptomycin has greater than 93% purity, less than 4% anhydro daptomycinand less than 4% β-isomer of daptomycin; and c) the compositioncomprising daptomycin is obtained by a purification process comprisingthe steps of forming a daptomycin aggregate and obtaining the daptomycinfrom the daptomycin aggregate.
 22. The pharmaceutical composition ofclaim 21, wherein the process for obtaining the daptomycin includes apurification process comprising the steps of a) subjecting daptomycin toanion exchange chromatography to obtain an enriched daptomycinpreparation; b) forming the daptomycin aggregate comprising a daptomycinmicelle in the enriched daptomycin preparation or a composition obtainedfrom the enriched daptomycin preparation; and c) obtaining thedaptomycin from the daptomycin aggregate.
 23. The pharmaceuticalcomposition of claim 22, wherein the daptomycin is obtained from thedaptomycin aggregate by a method comprising the steps of a) filteringthe daptomycin aggregate under conditions in which the daptomycinaggregate is retained on the filter; and b) collecting the daptomycinaggregate.
 24. The pharmaceutical composition of claim 23, wherein thedaptomycin is obtained from the daptomycin aggregate by a method furthercomprising the steps of a) subjecting a composition comprising thedaptomycin aggregate to hydrophobic interaction chromatography to obtaina semi-purified daptomycin preparation; and b) obtaining the daptomycinfrom the semi-purified daptomycin preparation.
 25. The composition ofclaim 17, wherein the infection of the blood, skin or soft tissuecomprises Staphylococcus aureus.
 26. The composition of claim 17,wherein the infection is bacteremia.
 27. The composition of claim 17,wherein the infection is endocarditis.
 28. The composition of claim 17,wherein the infection is a skin or soft tissue infection.
 29. Thecomposition of claim 17, wherein the infection includes bacteriaselected from the group consisting of Staphylococcus aureus,Streptococcus pyogenes, Streptococcus agalactiae, and Enterococcusfaecalis.
 30. A pharmaceutical composition for the treatment of aninfection, the composition comprising daptomycin having greater than 93%purity relative to impurities 1-14 defined by peaks 1-14 shown in FIG.12, the daptomycin purified by a process comprising the formation ofmicelles comprising daptomycin.
 31. The pharmaceutical composition ofclaim 30, wherein the daptomycin is a lyophilized powder comprisingdaptomycin purified by process comprising the steps of forming adaptomycin micelle and obtaining the daptomycin from the micelles. 32.The pharmaceutical composition of claim 31, wherein the daptomycin hasless than 4% anhydro daptomycin, less than 1% of the lactone hydrolysisproduct of daptomycin and is essentially free of the β-isomer ofdaptomycin.
 33. The pharmaceutical composition of claim 30, wherein thedaptomycin has less than 4% anhydro daptomycin and less than 4% β-isomerof daptomycin.
 34. The pharmaceutical composition of claim 30, whereinthe daptomycin has less than 1% of the lactone hydrolysis product ofdaptomycin.
 35. The composition of claim 30, wherein the infectioncomprises Staphylococcus aureus.
 36. The composition of claim 30,wherein the infection is bacteremia.
 37. The composition of claim 30,wherein the infection is endocarditis.
 38. The composition of claim 30,wherein the infection is a skin or soft tissue infection.
 39. Thecomposition of claim 30, wherein the infection includes bacteriaselected from the group consisting of Staphylococcus aureus,Streptococcus pyogenes, Streptococcus agalactiae, and Enterococcusfaecalis.
 40. A pharmaceutical composition for the treatment of aninfection of the blood, skin or soft tissue, the pharmaceuticalcomposition comprising a solution of a pharmaceutically acceptablecarrier for intravenous administration and daptomycin, the daptomycinhaving greater than 93% purity relative to impurities 1-14 defined bypeaks 1-14 shown in FIG. 12, and the daptomycin obtained from apurification process comprising the formation of a daptomycin micelle.41. The pharmaceutical composition of claim 40, wherein the daptomycinhas less than 4% anhydro daptomycin and less than 4% β-isomer ofdaptomycin.
 42. The pharmaceutical composition of claim 41, wherein thedaptomycin has less than 4% anhydro daptomycin, less than 1% of thelactone hydrolysis product of daptomycin and is essentially free of theβ-isomer of daptomycin.
 43. The pharmaceutical composition of claim 40,wherein the daptomycin has less than 1% of the lactone hydrolysisproduct of daptomycin.
 44. The composition of claim 40, wherein theinfection comprises Staphylococcus aureus.
 45. The composition of claim40, wherein the infection is bacteremia.
 46. The composition of claim40, wherein the infection is endocarditis.
 47. The composition of claim40 wherein the infection is a skin or soft tissue infection.
 48. Thecomposition of claim 40, wherein the infection includes bacteriaselected from the group consisting of Staphylococcus aureus,Streptococcus pyogenes, Streptococcus agalactiae, and Enterococcusfaecalis.
 49. The composition of claim 40, wherein the pharmaceuticalcomposition includes daptomycin in a daily intravenous dose 1 to 12mg/kg.
 50. A vial containing a lyophilized powder pharmaceuticalcomposition compatible with a pharmaceutically acceptable carrier forthe treatment of an infection by a daily intravenous dose of thelyophilized powder reconstituted in the pharmaceutically acceptablecarrier, the composition a) having daptomycin with greater than or about93% purity relative to impurities 1-14 defined by peaks 1-14 shown inFIG. 12; and b) the composition comprising daptomycin purified by aprocess including the steps of forming a daptomycin aggregate,converting the daptomycin aggregate to monomers and obtaining thedaptomycin in the composition from the monomers by a process includingone or more steps selected from the group consisting of anion exchangechromatography and hydrophobic interaction chromatography.
 51. Acomposition obtained by a process comprising the steps of forming adaptomycin aggregate, converting the daptomycin aggregate to monomersand obtaining the daptomycin in the composition from the monomers by aprocess including one or more steps selected from the group consistingof anion exchange chromatography and hydrophobic interactionchromatography, the composition comprising daptomycin of greater than orabout 93% purity relative to impurities 1-14 defined by peaks 1-14 shownin FIG.
 12. 52. The composition of claim 51, comprising daptomycin ofgreater than 93% purity relative to impurities 1-14 defined by peaks1-14 shown in FIG.
 12. 53. The composition of claim 52, wherein a) thecomposition is a lyophilized powder compatible with a pharmaceuticallyacceptable carrier for the treatment of an infection by a dailyintravenous dose of 1 to 12 mg/kg of the daptomycin in a reconstitutedsolution of the lyophilized powder in the pharmaceutically acceptablecarrier; and b) the daptomycin has a purity of about 94 to 96% relativeto impurities 1-14 defined by peaks 1-14 shown in FIG. 12, thedaptomycin having less than 1% of the lactone hydrolysis product ofdaptomycin, less than 4% anhydro daptomycin and less than 4% of theβ-isomer of daptomycin.
 54. The composition of claim 51, wherein thecomposition is a lyophilized powder compatible with a pharmaceuticallyacceptable carrier for the treatment of one or more infections selectedfrom the group consisting of infections of the blood, skin and softtissue, by a daily intravenous dose of 1 to 12 mg/kg of the daptomycinin a reconstituted solution of the lyophilized powder in thepharmaceutically acceptable carrier.